National Library of Energy BETA

Sample records for model involves iterative

  1. ITER neutralizer modeling (abstract)

    SciTech Connect (OSTI)

    Minea, T.; Lifschitz, A.; Maynard, G.; Katsonis, K.; Bretagne, J.; Simonin, A.

    2008-02-15

    In the neutralizer of the ITER Neutral Beam Injector, a 1 MeV-D{sup -} beam passes through an structure filled with D{sub 2} gas, where negative ions are mainly converted to fast D{sup 0} atoms. Once that the beam is neutralized no further optical correction is possible, i.e., transport from the neutralizer to the confinement chamber is ballistic. Because of this, the transport through the neutralizer determines ultimately the geometrical properties of the neutral beams. The ionization of the buffer gas (D{sub 2}) filling the neutralizer induced by the D beam creates a rarefied and low temperature plasma (ionization degree {approx_equal}10{sup -3}, electron temperature {approx_equal}20 eV). This plasma can screen the electrostatic well of the D beam and, consequently, affect the properties of the extracted beam and the energy transport to the neutralizer walls. On the other hand, the plasma will eventually escape from the neutralizer and move back in the accelerator chain, toward the accelerating grids and the source. We present particle-in-cell simulations of the beam propagation and plasma formation through the neutralizer. Particle-particle and particle-wall collisions are treated using a Monte Carlo approach. Simulations show that the secondary plasma effectively screens the beam space charge preventing beam radial expansion due to Coulomb repulsion between beam ions. First results suggest that the current of plasma ions (D{sub 2}{sup +}) into the accelerator would be of the order of I(D{sup -})/100, with I(D{sup -}) the negative ion current.

  2. STELLOPT Modeling of the 3D Diagnostic Response in ITER

    SciTech Connect (OSTI)

    Lazerson, Samuel A

    2013-05-07

    The ITER three dimensional diagnostic response to an n=3 resonant magnetic perturbation is modeled using the STELLOPT code. The in-vessel coils apply a resonant magnetic perturbation (RMP) fi eld which generates a 4 cm edge displacement from axisymmetry as modeled by the VMEC 3D equilibrium code. Forward modeling of flux loop and magnetic probe response with the DIAGNO code indicates up to 20 % changes in measured plasma signals. Simulated LIDAR measurements of electron temperature indicate 2 cm shifts on the low field side of the plasma. This suggests that the ITER diagnostic will be able to diagnose the 3D structure of the equilibria.

  3. Modeling Results For the ITER Cryogenic Fore Pump. Final Report

    SciTech Connect (OSTI)

    Pfotenhauer, John M.; Zhang, Dongsheng

    2014-03-31

    A numerical model characterizing the operation of a cryogenic fore-pump (CFP) for ITER has been developed at the University of Wisconsin – Madison during the period from March 15, 2011 through June 30, 2014. The purpose of the ITER-CFP is to separate hydrogen isotopes from helium gas, both making up the exhaust components from the ITER reactor. The model explicitly determines the amount of hydrogen that is captured by the supercritical-helium-cooled pump as a function of the inlet temperature of the supercritical helium, its flow rate, and the inlet conditions of the hydrogen gas flow. Furthermore the model computes the location and amount of hydrogen captured in the pump as a function of time. Throughout the model’s development, and as a calibration check for its results, it has been extensively compared with the measurements of a CFP prototype tested at Oak Ridge National Lab. The results of the model demonstrate that the quantity of captured hydrogen is very sensitive to the inlet temperature of the helium coolant on the outside of the cryopump. Furthermore, the model can be utilized to refine those tests, and suggests methods that could be incorporated in the testing to enhance the usefulness of the measured data.

  4. Modeling results for the ITER cryogenic fore pump

    SciTech Connect (OSTI)

    Zhang, D. S.; Miller, F. K.; Pfotenhauer, J. M.

    2014-01-29

    The cryogenic fore pump (CFP) is designed for ITER to collect and compress hydrogen isotopes during the regeneration process of torus cryopumps. Different from common cryopumps, the ITER-CFP works in the viscous flow regime. As a result, both adsorption boundary conditions and transport phenomena contribute unique features to the pump performance. In this report, the physical mechanisms of cryopumping are studied, especially the diffusion-adsorption process and these are coupled with standard equations of species, momentum and energy balance, as well as the equation of state. Numerical models are developed, which include highly coupled non-linear conservation equations of species, momentum and energy and equation of state. Thermal and kinetic properties are treated as functions of temperature, pressure, and composition. To solve such a set of equations, a novel numerical technique, identified as the Group-Member numerical technique is proposed. It is presented here a 1D numerical model. The results include comparison with the experimental data of pure hydrogen flow and a prediction for hydrogen flow with trace helium. An advanced 2D model and detailed explanation of the Group-Member technique are to be presented in following papers.

  5. US ITER | Media Corner

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    In Jacob's Room at US ITER In Jacob's Room at US ITER College Student Models, Simulates and Designs a Cooling Subsystem for the ITER Tokamak -Agatha Bardoel Published June 24, 2011 ...

  6. Mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models

    SciTech Connect (OSTI)

    Corcelli, S.A.; Kress, J.D.; Pratt, L.R.

    1995-08-07

    This paper develops and characterizes mixed direct-iterative methods for boundary integral formulations of continuum dielectric solvation models. We give an example, the Ca{sup ++}{hor_ellipsis}Cl{sup {minus}} pair potential of mean force in aqueous solution, for which a direct solution at thermal accuracy is difficult and, thus for which mixed direct-iterative methods seem necessary to obtain the required high resolution. For the simplest such formulations, Gauss-Seidel iteration diverges in rare cases. This difficulty is analyzed by obtaining the eigenvalues and the spectral radius of the non-symmetric iteration matrix. This establishes that those divergences are due to inaccuracies of the asymptotic approximations used in evaluation of the matrix elements corresponding to accidental close encounters of boundary elements on different atomic spheres. The spectral radii are then greater than one for those diverging cases. This problem is cured by checking for boundary element pairs closer than the typical spatial extent of the boundary elements and for those cases performing an ``in-line`` Monte Carlo integration to evaluate the required matrix elements. These difficulties are not expected and have not been observed for the thoroughly coarsened equations obtained when only a direct solution is sought. Finally, we give an example application of hybrid quantum-classical methods to deprotonation of orthosilicic acid in water.

  7. A new frequency domain arc furnace model for iterative harmonic analysis

    SciTech Connect (OSTI)

    Mayordomo, J.G.; Beites, L.F.; Asensi, R.; Izzeddine, M.; Zabala, L.; Amantegui, J.

    1997-10-01

    This paper presents a new frequency domain Arc Furnace model for Iterative Harmonic Analysis (IHA) by means of a Newton method. Powerful analytical expressions for harmonic currents and their derivatives are obtained under the balanced conditions of the system. The model offers a three phase configuration where there is no path for homopolar currents. Moreover, it contemplates continuous and discontinuous evolution of the arc current. The solution obtained is validated by means of time domain simulations. Finally, the model was integrated in a harmonic power flow where studies have been performed in a network with more than 700 busbars and 7 actual Arc Furnace Loads.

  8. US ITER

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    ... Central Solenoid Fabrication: A Photo Reportage ITER Newsline, July 18, 2016 Shooting selected pellets into the plasma ITER Newsline, June 13, 2016 General Atomics Applauds ...

  9. Modeling and simulation of a beam emission spectroscopy diagnostic for the ITER prototype neutral beam injector

    SciTech Connect (OSTI)

    Barbisan, M. Zaniol, B.; Pasqualotto, R.

    2014-11-15

    A test facility for the development of the neutral beam injection system for ITER is under construction at Consorzio RFX. It will host two experiments: SPIDER, a 100 keV H{sup −}/D{sup −} ion RF source, and MITICA, a prototype of the full performance ITER injector (1 MV, 17 MW beam). A set of diagnostics will monitor the operation and allow to optimize the performance of the two prototypes. In particular, beam emission spectroscopy will measure the uniformity and the divergence of the fast particles beam exiting the ion source and travelling through the beam line components. This type of measurement is based on the collection of the H{sub α}/D{sub α} emission resulting from the interaction of the energetic particles with the background gas. A numerical model has been developed to simulate the spectrum of the collected emissions in order to design this diagnostic and to study its performance. The paper describes the model at the base of the simulations and presents the modeled H{sub α} spectra in the case of MITICA experiment.

  10. Validation of the thermal transport model used for ITER startup scenario predictions with DIII-D experimental data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Casper, T. A.; Meyer, W. H.; Jackson, G. L.; Luce, T. C.; Hyatt, A. W.; Humphreys, D. A.; Turco, F.

    2010-12-08

    We are exploring characteristics of ITER startup scenarios in similarity experiments conducted on the DIII-D Tokamak. In these experiments, we have validated scenarios for the ITER current ramp up to full current and developed methods to control the plasma parameters to achieve stability. Predictive simulations of ITER startup using 2D free-boundary equilibrium and 1D transport codes rely on accurate estimates of the electron and ion temperature profiles that determine the electrical conductivity and pressure profiles during the current rise. Here we present results of validation studies that apply the transport model used by the ITER team to DIII-D discharge evolutionmore » and comparisons with data from our similarity experiments.« less

  11. Modeling and Simulation of the ITER First Wall/Blanket Primary Heat Transfer System

    SciTech Connect (OSTI)

    Ying, Alice; Popov, Emilian L

    2011-01-01

    ITER inductive power operation is modeled and simulated using a thermal-hydraulics system code (RELAP5) integrated with a 3-D CFD (SC-Tetra) code. The Primary Heat Transfer System (PHTS) functions are predicted together with the main parameters operational ranges. The control algorithm strategy and derivation are summarized as well. The First Wall and Blanket modules are the primary components of PHTS, used to remove the major part of the thermal heat from the plasma. The modules represent a set of flow channels in solid metal structure that serve to absorb the radiation heat and nuclear heating from the fusion reactions and to provide shield for the vacuum vessel. The blanket modules are water cooled. The cooling is forced convective with constant blanket inlet temperature and mass flow rate. Three independent water loops supply coolant to the three blanket sectors. The main equipment of each loop consists of a pump, a steam pressurizer and a heat exchanger. A major feature of ITER is the pulsed operation. The plasma does not burn continuously, but on intervals with large periods of no power between them. This specific feature causes design challenges to accommodate the thermal expansion of the coolant during the pulse period and requires active temperature control to maintain a constant blanket inlet temperature.

  12. US ITER | Media Corner

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    Fact Sheets Fact Sheets Hydrogen Fusion ITER Project US ITER Progress US ITER Participants US ITER Participants Pin Map US ITER Hardware: Central Solenoid (CS) Tokamak Cooling ...

  13. Helium embrittlement model and program plan for weldability of ITER materials

    SciTech Connect (OSTI)

    Louthan, M.R. Jr.; Kanne, W.R. Jr.; Tosten, M.H.; Rankin, D.T.; Cross, B.J.

    1997-02-01

    This report presents a refined model of how helium embrittles irradiated stainless steel during welding. The model was developed based on experimental observations drawn from experience at the Savannah River Site and from an extensive literature search. The model shows how helium content, stress, and temperature interact to produce embrittlement. The model takes into account defect structure, time, and gradients in stress, temperature and composition. The report also proposes an experimental program based on the refined helium embrittlement model. A parametric study of the effect of initial defect density on the resulting helium bubble distribution and weldability of tritium aged material is proposed to demonstrate the roll that defects play in embrittlement. This study should include samples charged using vastly different aging times to obtain equivalent helium contents. Additionally, studies to establish the minimal sample thickness and size are needed for extrapolation to real structural materials. The results of these studies should provide a technical basis for the use of tritium aged materials to predict the weldability of irradiated structures. Use of tritium charged and aged material would provide a cost effective approach to developing weld repair techniques for ITER components.

  14. SU-E-I-33: Initial Evaluation of Model-Based Iterative CT Reconstruction Using Standard Image Quality Phantoms

    SciTech Connect (OSTI)

    Gingold, E; Dave, J

    2014-06-01

    Purpose: The purpose of this study was to compare a new model-based iterative reconstruction with existing reconstruction methods (filtered backprojection and basic iterative reconstruction) using quantitative analysis of standard image quality phantom images. Methods: An ACR accreditation phantom (Gammex 464) and a CATPHAN600 phantom were scanned using 3 routine clinical acquisition protocols (adult axial brain, adult abdomen, and pediatric abdomen) on a Philips iCT system. Each scan was acquired using default conditions and 75%, 50% and 25% dose levels. Images were reconstructed using standard filtered backprojection (FBP), conventional iterative reconstruction (iDose4) and a prototype model-based iterative reconstruction (IMR). Phantom measurements included CT number accuracy, contrast to noise ratio (CNR), modulation transfer function (MTF), low contrast detectability (LCD), and noise power spectrum (NPS). Results: The choice of reconstruction method had no effect on CT number accuracy, or MTF (p<0.01). The CNR of a 6 HU contrast target was improved by 167% with iDose4 relative to FBP, while IMR improved CNR by 145367% across all protocols and dose levels. Within each scan protocol, the CNR improvement from IMR vs FBP showed a general trend of greater improvement at lower dose levels. NPS magnitude was greatest for FBP and lowest for IMR. The NPS of the IMR reconstruction showed a pronounced decrease with increasing spatial frequency, consistent with the unusual noise texture seen in IMR images. Conclusion: Iterative Model Reconstruction reduces noise and improves contrast-to-noise ratio without sacrificing spatial resolution in CT phantom images. This offers the possibility of radiation dose reduction and improved low contrast detectability compared with filtered backprojection or conventional iterative reconstruction.

  15. Modeling and Analysis of Alternative Concept of ITER Vacuum Vessel Primary Heat Transfer System

    SciTech Connect (OSTI)

    Carbajo, Juan J; Yoder Jr, Graydon L; Dell'Orco, Giovanni; Curd, Warren; Kim, Seokho H

    2010-01-01

    A RELAP5-3D model of the ITER (Latin for the way ) vacuum vessel (VV) primary heat transfer system has been developed to evaluate a proposed design change that relocates the heat exchangers (HXs) from the exterior of the tokamak building to the interior. This alternative design protects the HXs from external hazards such as wind, tornado, and aircraft crash. The proposed design integrates the VV HXs into a VV pressure suppression system (VVPSS) tank that contains water to condense vapour in case of a leak into the plasma chamber. The proposal is to also use this water as the ultimate sink when removing decay heat from the VV system. The RELAP5-3D model has been run under normal operating and abnormal (decay heat) conditions. Results indicate that this alternative design is feasible, with no effects on the VVPSS tank under normal operation and with tank temperature and pressure increasing under decay heat conditions resulting in a requirement to remove steam generated if the VVPSS tank low pressure must be maintained.

  16. US ITER | Jobs

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    Postings Careers in Fusion Science ITER Jobs Home > Jobs > US ITER Positions US ITER Positions US

  17. Circuit model of the ITER-like antenna for JET and simulation of its control algorithms

    SciTech Connect (OSTI)

    Durodié, Frédéric Křivská, Alena; Helou, Walid; Collaboration: EUROfusion Consortium

    2015-12-10

    The ITER-like Antenna (ILA) for JET [1] is a 2 toroidal by 2 poloidal array of Resonant Double Loops (RDL) featuring in-vessel matching capacitors feeding RF current straps in conjugate-T manner, a low impedance quarter-wave impedance transformer, a service stub allowing hydraulic actuator and water cooling services to reach the aforementioned capacitors and a 2nd stage phase-shifter-stub matching circuit allowing to correct/choose the conjugate-T working impedance. Toroidally adjacent RDLs are fed from a 3dB hybrid splitter. It has been operated at 33, 42 and 47MHz on plasma (2008-2009) while it presently estimated frequency range is from 29 to 49MHz. At the time of the design (2001-2004) as well as the experiments the circuit models of the ILA were quite basic. The ILA front face and strap array Topica model was relatively crude and failed to correctly represent the poloidal central septum, Faraday Screen attachment as well as the segmented antenna central septum limiter. The ILA matching capacitors, T-junction, Vacuum Transmission Line (VTL) and Service Stubs were represented by lumped circuit elements and simple transmission line models. The assessment of the ILA results carried out to decide on the repair of the ILA identified that achieving routine full array operation requires a better understanding of the RF circuit, a feedback control algorithm for the 2nd stage matching as well as tighter calibrations of RF measurements. The paper presents the progress in modelling of the ILA comprising a more detailed Topica model of the front face for various plasma Scrape Off Layer profiles, a comprehensive HFSS model of the matching capacitors including internal bellows and electrode cylinders, 3D-EM models of the VTL including vacuum ceramic window, Service stub, a transmission line model of the 2nd stage matching circuit and main transmission lines including the 3dB hybrid splitters. A time evolving simulation using the improved circuit model allowed to design and

  18. US ITER | Doing Business

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    U.S. ITER > Business Opportunities Business Opportunities U.S. ITER International ITER International Organization (IO) Competitive Task Agreements ITER International Department of ...

  19. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    SciTech Connect (OSTI)

    Almansouri, Hani; Clayton, Dwight A; Kisner, Roger A; Polsky, Yarom; Bouman, Charlie; Santos-Villalobos, Hector J

    2015-01-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well s health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.

  20. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    SciTech Connect (OSTI)

    Almansouri, Hani; Clayton, Dwight A; Kisner, Roger A; Polsky, Yarom; Bouman, Charlie; Santos-Villalobos, Hector J

    2016-01-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.

  1. Quasi-linear modeling of lower hybrid current drive in ITER and DEMO

    SciTech Connect (OSTI)

    Cardinali, A. Cesario, R.; Panaccione, L.; Santini, F.; Amicucci, L.; Castaldo, C.; Ceccuzzi, S.; Mirizzi, F.; Tuccillo, A. A.

    2015-12-10

    First pass absorption of the Lower Hybrid waves in thermonuclear devices like ITER and DEMO is modeled by coupling the ray tracing equations with the quasi-linear evolution of the electron distribution function in 2D velocity space. As usually assumed, the Lower Hybrid Current Drive is not effective in a plasma of a tokamak fusion reactor, owing to the accessibility condition which, depending on the density, restricts the parallel wavenumber to values greater than n{sub ∥crit} and, at the same time, to the high electron temperature that would enhance the wave absorption and then restricts the RF power deposition to the very periphery of the plasma column (near the separatrix). In this work, by extensively using the “ray{sup star}” code, a parametric study of the propagation and absorption of the LH wave as function of the coupled wave spectrum (as its width, and peak value), has been performed very accurately. Such a careful investigation aims at controlling the power deposition layer possibly in the external half radius of the plasma, thus providing a valuable aid to the solution of how to control the plasma current profile in a toroidal magnetic configuration, and how to help the suppression of MHD mode that can develop in the outer part of the plasma. This analysis is useful not only for exploring the possibility of profile control of a pulsed operation reactor as well as the tearing mode stabilization, but also in order to reconsider the feasibility of steady state regime for DEMO.

  2. US ITER | Jobs

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    Postings Careers in Fusion Science ITER Jobs Home > Jobs > International Job Postings International ITER Postions International

  3. US ITER | About

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    US ITER About US ITER ABOUT US ITER | WHY FUSION? | DOING BUSINESS WITH US ITER | MEDIA CORNER | JOBS | CONTACT US About US ITER US Hardware Contributions About US ITER Home > About US ITER Background US ITER is a DOE Office of Science project hosted by Oak Ridge National Laboratory in Tennessee. Partner labs are Princeton Plasma Physics Laboratory and Savannah River National Laboratory. The US is a partner nation in ITER, an unprecedented international collaboration of scientists and

  4. US ITER | Media Corner

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    Schedule Concerns Delay ITER's Go-Ahead Science Magazine, November 27, 2009 ITER council delays project Physics Today, November 20, 2009 ITER Blueprints Near Completion, But ...

  5. US ITER | Media Corner

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    Building the heartbeat of ITER Building the heartbeat of ITER US ITER prepares for the fabrication of the international fusion reactor's central solenoid -Lynne Degitz Published ...

  6. US ITER | Doing Business

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    Opportunties > For Vendors For Vendors US ITER Vendor Database (For US ITER internal use only) Vendor Account Status System ORNL Procurement ITER International Department of Energy ...

  7. What is ITER

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    ITER? ITER is a large international fusion experiment aimed at demonstrating the scientific and technological feasibility of fusion energy. ITER (Latin for "the way") will play a ...

  8. Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance

    SciTech Connect (OSTI)

    Li, Ke; Tang, Jie; Chen, Guang-Hong

    2014-04-15

    Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup }, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a redder NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP

  9. US ITER | Doing Business

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    ITER International Organization Competitive Task Agreements International Organization ... ITER International Department of Energy Office of Science Oak Ridge National Laboratory ...

  10. US ITER | Media Corner

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    Neutronics at Wisconsin, ORNL advances ITER shielding and international collaboration "Neutronics" at Wisconsin, ORNL advances ITER shielding and international collaboration ...

  11. US ITER | Doing Business

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    Business Opportunties > ITER Clauses, Documents & Forms ITER Clauses, Documents & Forms Technical Proposal Disclosure Policy (April 2013) Identification of Background Intellectual ...

  12. US ITER | Media Corner

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    Mitigating plasma disruptions in ITER Mitigating plasma disruptions in ITER Using large cryogenic pellets, US ITER advances new fusion technology -Lynne Degitz Published September 18, 2014 A three-barrel pellet injector developed at Oak Ridge National Laboratory for the ITER disruption mitigation system. Photo: US ITER/ORNL. A three-barrel pellet injector developed at Oak Ridge National Laboratory for the ITER disruption mitigation system. Photo: US ITER/ORNL The international ITER fusion

  13. US ITER | Media Corner

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    Corner Fact Sheets Hydrogen Fusion ITER Project US ITER Progress US ITER Participants More Project Background Creating a Star - The Global ITER Partnership Features and Highlights Central Solenoid Fabrication: A Photo Reportage [ITER Newsline, July 18, 2016] Shooting selected pellets into the plasma [ITER Newsline, June 13, 2016] Winding completed on first central solenoid module [ITER Newsline, Arpril 11, 2016] Fusion diagnostics heat up across the US [US ITER, October 22, 2015] Preparing a

  14. ITER | Princeton Plasma Physics Lab

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    ITER What is ITER? ITER is a large international fusion experiment aimed at demonstrating the scientific and technological feasibility of fusion energy. ITER (Latin for "the way") ...

  15. US ITER | Media Corner

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    Subscribe to the US ITER Newsletter Need an Expert? Media are welcome to contact Mark Uhran for assistance in reaching an appropriate US ITER expert. US ITER staff members are also ...

  16. US ITER | Jobs

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    Nicolai Martovetsky US ITER Magnet Systems R&D Manager and Chief Engineer Tell us about ... What were you doing before you came to US ITER? Before coming to US ITER, I was a research ...

  17. US ITER | Media Corner

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    New Division Management in Place at US ITER New Division Management in Place at US ITER Published September 20, 2011 After an extensive international search, US ITER selected John ...

  18. US ITER | Media Corner

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    India DA Project Director Visits US ITER Project Office India DA Project Director Visits US ITER Project Office Published Janaury 5, 2012 India DA Project Director Visits US ITER ...

  19. IDC RE-Engineering Phase 2 Iteration E1 Use Case Model Survey.

    SciTech Connect (OSTI)

    Harris, James M.; Carr, Dorthe B.; Coram, Jamie L.

    2016-01-01

    This document contains the brief descriptions for the actors and use cases contained in the IDC Use Case Model.

  20. US ITER | About

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    Electron Cyclotron Heating System Image Highlighted in pink: ITER Electron Cyclotron ... For more information, contact: David Rasmussen, US ITER Project Office EC Transmission ...

  1. US ITER | Media Corner

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    US ITER preps for high performance plasma heating US ITER preps for high performance plasma heating New test results and innovations advance ion cyclotron high power transmission ...

  2. US ITER | Media Corner

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    fabrication of early delivery components for ITER advances US fabrication of early delivery components for ITER advances Delivery of tokamak cooling water system drain tanks will ...

  3. US ITER | Contact Us

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    Organizational Charts ABOUT US ITER | WHY FUSION? | DOING BUSINESS WITH US ITER | MEDIA CORNER | JOBS | CONTACT US Visitor Information Key Contact Staff Directory Organizational ...

  4. US ITER | Doing Business

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    process for one of the above International ITER Organization requirements, please review ... Jeff Geouque Oak Ridge National Laboratory Procurement Director US ITER Project Email: ...

  5. US ITER | Doing Business

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    US Business Opportunities US Business Opportunities Upcoming US ITER Procurements WBS ... for Proposal POC - Point of Contact ITER International Department of Energy Office ...

  6. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    This visualization demonstrates how the ITER reactor will create a burning plasma. ... Tokamak Complex- April 2012 An overview of construction progress for the ITER tokmak ...

  7. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fact Sheet ICH Image Highlighted in pink: ITER Ion Cyclotron Heating Transmission Lines. ... For more information, contact: David Rasmussen, US ITER Project Office EC Transmission ...

  8. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutron Science Division, November 22, 2006 US ITER Project Completes Management Team ORNL News Release, August 17, 2006 US ITER Project Office, a partnership of Princeton ...

  9. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Welcome to East Tennessee, Oak Ridge National Laboratory (ORNL), and the U.S. ITER Project ... Accommodations Area Guides Food Local Media Maps Transportation Weather ITER International ...

  10. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    advantages for US ITER engineers Desktop additive printers are changing the engineering design process 3D printing yields advantages for US ITER engineers Desktop additive ...

  11. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Testing Central Solenoid Structural Integrity Key steps forward for US ITER magnet efforts ... vessel will be used in testing methods for sealing and insulating ITER magnet modules. ...

  12. US ITER | Doing Business

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    International: Business Opportunities with Other International Partners European Union The European Union maintains a website with additional ITER Business Opportunities. ITER ...

  13. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vacuum Auxiliary Systems (WBS 1.3.1) Fact Sheet ITER Vacuum Vessle and Cryostat Image ... pumps and vacuum auxiliary system. The ITER tokamak, cryostat, and auxiliary vacuum ...

  14. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bardoel Published February 22, 2012 US ITER Toridal Field Coil Conductor US ITER toroidal field coil conductor production requires miles of niobium-tin superconducting wire. ...

  15. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New Procurement Arrangement Signed for Low Field Side Reflectometer Diagnostic -Agatha Bardoel Published June 21, 2012 US ITER Project Manger Ned Sauthoff and ITER Director-General ...

  16. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    UT Magnet Lab Advances US ITER and Next Generation of Engineers, Scientists UT Magnet Lab Advances US ITER and Next Generation of Engineers, Scientists -Agatha Bardoel Published ...

  17. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cooling Water Systems Image Highlighted in pink: ITER Tokamak Cooling Water System. The US ... The TCWS interfaces with the majority of ITER systems, including the secondary cooling ...

  18. US ITER | Doing Business

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER > Business Opportunties > For Vendors > Tokamak Cooling Water System Opportunities Tokamak Cooling Water System (TCWS) Opportunities US ITER has contracted with AREVA...

  19. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A port plug integration proposal developed with the US ITER diagnostics team has helped the international ITER collaboration arrive at a clever solution for safely housing all of ...

  20. Progress report on the behavior and modeling of copper alloy to stainless steel joints for ITER first wall applications

    SciTech Connect (OSTI)

    Min, J.; Stubbins, J.; Collins, J.; Rowcliffe, A.F.

    1998-09-01

    The stress states that lead to failure of joints between GlidCop{trademark} CuAl25 and 316L SS were examined using finite element modeling techniques to explain experimental observations of behavior of those joints. The joints were formed by hot isostatic pressing (HIP) and bend bar specimens were fabricated with the joint inclined 45{degree} to the major axis of the specimen. The lower surface of the bend bar was notched in order to help induce a precrack for subsequent loading in bending. The precrack was intended to localize a high stress concentration in close proximity to the interface so that its behavior could be examined without complicating factors from the bulk materials and the specimen configuration. Preparatory work to grow acceptable precracks caused the specimen to fail prematurely while the precrack was still progressing into the specimen toward the interface. This prompted the finite element model calculations to help understand the reasons for this behavior from examination of the stress states throughout the specimen. An additional benefit sought from the finite element modeling effort was to understand if the stress states in this non-conventional specimen were representative of those that might be experienced during operation in ITER.

  1. Characterization of a commercial hybrid iterative and model-based reconstruction algorithm in radiation oncology

    SciTech Connect (OSTI)

    Price, Ryan G.; Vance, Sean; Cattaneo, Richard; Elshaikh, Mohamed A.; Chetty, Indrin J.; Glide-Hurst, Carri K.; Schultz, Lonni

    2014-08-15

    Purpose: Iterative reconstruction (IR) reduces noise, thereby allowing dose reduction in computed tomography (CT) while maintaining comparable image quality to filtered back-projection (FBP). This study sought to characterize image quality metrics, delineation, dosimetric assessment, and other aspects necessary to integrate IR into treatment planning. Methods: CT images (Brilliance Big Bore v3.6, Philips Healthcare) were acquired of several phantoms using 120 kVp and 25–800 mAs. IR was applied at levels corresponding to noise reduction of 0.89–0.55 with respect to FBP. Noise power spectrum (NPS) analysis was used to characterize noise magnitude and texture. CT to electron density (CT-ED) curves were generated over all IR levels. Uniformity as well as spatial and low contrast resolution were quantified using a CATPHAN phantom. Task specific modulation transfer functions (MTF{sub task}) were developed to characterize spatial frequency across objects of varied contrast. A prospective dose reduction study was conducted for 14 patients undergoing interfraction CT scans for high-dose rate brachytherapy. Three physicians performed image quality assessment using a six-point grading scale between the normal-dose FBP (reference), low-dose FBP, and low-dose IR scans for the following metrics: image noise, detectability of the vaginal cuff/bladder interface, spatial resolution, texture, segmentation confidence, and overall image quality. Contouring differences between FBP and IR were quantified for the bladder and rectum via overlap indices (OI) and Dice similarity coefficients (DSC). Line profile and region of interest analyses quantified noise and boundary changes. For two subjects, the impact of IR on external beam dose calculation was assessed via gamma analysis and changes in digitally reconstructed radiographs (DRRs) were quantified. Results: NPS showed large reduction in noise magnitude (50%), and a slight spatial frequency shift (∼0.1 mm{sup −1}) with

  2. A model of lipid-free Apolipoprotein A-I revealed by iterative molecular dynamics simulation

    SciTech Connect (OSTI)

    Zhang, Xing; Lei, Dongsheng; Zhang, Lei; Rames, Matthew; Zhang, Shengli

    2015-03-20

    Apolipoprotein A-I (apo A-I), the major protein component of high-density lipoprotein, has been proven inversely correlated to cardiovascular risk in past decades. The lipid-free state of apo A-I is the initial stage which binds to lipids forming high-density lipoprotein. Molecular models of lipid-free apo A-I have been reported by methods like X-ray crystallography and chemical cross-linking/mass spectrometry (CCL/MS). Through structural analysis we found that those current models had limited consistency with other experimental results, such as those from hydrogen exchange with mass spectrometry. Through molecular dynamics simulations, we also found those models could not reach a stable equilibrium state. Therefore, by integrating various experimental results, we proposed a new structural model for lipidfree apo A-I, which contains a bundled four-helix N-terminal domain (1–192) that forms a variable hydrophobic groove and a mobile short hairpin C-terminal domain (193–243). This model exhibits an equilibrium state through molecular dynamics simulation and is consistent with most of the experimental results known from CCL/MS on lysine pairs, fluorescence resonance energy transfer and hydrogen exchange. This solution-state lipid-free apo A-I model may elucidate the possible conformational transitions of apo A-I binding with lipids in high-density lipoprotein formation.

  3. A model of lipid-free Apolipoprotein A-I revealed by iterative molecular dynamics simulation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, Xing; Lei, Dongsheng; Zhang, Lei; Rames, Matthew; Zhang, Shengli

    2015-03-20

    Apolipoprotein A-I (apo A-I), the major protein component of high-density lipoprotein, has been proven inversely correlated to cardiovascular risk in past decades. The lipid-free state of apo A-I is the initial stage which binds to lipids forming high-density lipoprotein. Molecular models of lipid-free apo A-I have been reported by methods like X-ray crystallography and chemical cross-linking/mass spectrometry (CCL/MS). Through structural analysis we found that those current models had limited consistency with other experimental results, such as those from hydrogen exchange with mass spectrometry. Through molecular dynamics simulations, we also found those models could not reach a stable equilibrium state. Therefore,more » by integrating various experimental results, we proposed a new structural model for lipidfree apo A-I, which contains a bundled four-helix N-terminal domain (1–192) that forms a variable hydrophobic groove and a mobile short hairpin C-terminal domain (193–243). This model exhibits an equilibrium state through molecular dynamics simulation and is consistent with most of the experimental results known from CCL/MS on lysine pairs, fluorescence resonance energy transfer and hydrogen exchange. This solution-state lipid-free apo A-I model may elucidate the possible conformational transitions of apo A-I binding with lipids in high-density lipoprotein formation.« less

  4. Review of recent experimental and modeling progress in the lower hybrid range of frequencies at ITER relevant parameters

    SciTech Connect (OSTI)

    Bonoli, Paul T.

    2014-02-12

    Progress in experiment and simulation capability in the lower hybrid range of frequencies (LHRF) at ITER relevant parameters is reviewed. Use of LH power in reactor devices is motivated in terms of its potential for efficient off-axis current profile control. Recent improvements in simulation capability including the development of full-wave field solvers, inclusion of the scrape off layer (SOL) in wave propagation codes, the use of coupled ray tracing / full-wave / 3D (r v{sub ?}, v{sub ?}) Fokker Planck models, and the inclusion of nonlinear broadening effects in ray tracing / Fokker Planck codes are discussed. Experimental and modeling results are reviewed which are aimed at understanding the spectral gap problem in LH current drive (LHCD) and the density limit that has been observed in LHCD experiments. Physics mechanisms that could be operative in these experiments are discussed, including toroidally induced variations in the parallel wavenumber, nonlinear broadening of the pump wave, scattering of LH waves from density fluctuations in the SOL, and spectral broadening at the plasma edge via full-wave effects.

  5. Review of recent experimental and modeling progress in the lower hybrid range of frequencies at ITER relevant parameters

    SciTech Connect (OSTI)

    Bonoli, Paul T.

    2014-06-15

    Progress in experiment and simulation capability in the lower hybrid range of frequencies at ITER relevant parameters is reviewed. Use of LH power in reactor devices is motivated in terms of its potential for efficient off-axis current profile control. Recent improvements in simulation capability including the development of full-wave field solvers, inclusion of the scrape off layer (SOL) in wave propagation codes, the use of coupled ray tracing/full-wave/3D (r v{sub ⊥}, v{sub //}) Fokker Planck models, and the inclusion of wave scattering as well as nonlinear broadening effects in ray tracing / Fokker Planck codes are discussed. Experimental and modeling results are reviewed which are aimed at understanding the spectral gap problem in LH current drive (LHCD) and the density limit that has been observed and mitigated in LHCD experiments. Physics mechanisms that could be operative in these experiments are discussed, including toroidally induced variations in the parallel wavenumber, nonlinear broadening of the pump wave, scattering of LH waves from density fluctuations in the SOL, and spectral broadening at the plasma edge via full-wave effects.

  6. US ITER | Jobs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER Jobs ABOUT US ITER | WHY FUSION? | DOING BUSINESS WITH US ITER | MEDIA CORNER | JOBS | CONTACT US US Job Postings International Job Postings Careers in Fusion Science ITER Jobs Home > US ITER Jobs Be a Part of Something Big! US ITER is a Department of Energy multi-laboratory project that executes the US contributions to ITER for the US. The US is a non-host partner in the seven-member international collaboration between the United States, China, India, Japan, Korea, Russia, and the

  7. US ITER | Doing Business

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER US ITER Procurement Division is responsible for the acquisition of goods and services for the US ITER project. Business Opportunities US: Upcoming US ITER Procurements US: Business Opportunities with Other Partner Laboratories International: Calls for Nominations, Calls for Expertise and Market Surveys/Requests for Interest International: Opportunities with Other International Partners ITER International Organization (IO) Competitive Task Agreements. For Vendors Vendors wishing to do

  8. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Central solenoid insert coil confirms conductor readiness for ITER Central solenoid insert coil confirms conductor readiness for ITER Central solenoid insert coil confirms conductor readiness for ITER -Lynne Degitz Published August 13, 2015 The insert coil being lowered into the test facility at Naka, Japan. The insert coil being lowered into the test facility at Naka, Japan. Photo: JAEA In another step towards building the ITER fusion reactor, the US ITER team worked with international partners

  9. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER pump design benefits from testing at ORNL Spallation Neutron Source cryogenic facility ITER pump design benefits from testing at ORNL Spallation Neutron Source cryogenic facility ITER pump design benefits from testing at ORNL Spallation Neutron Source cryogenic facility -Lynne Degitz Published August 4, 2015 Robert Duckworth oversaw the testing of the 9-foot tall ITER cryoviscous compress pump prototype at the Spallation Neutron Source cryogenic test facility. Photo: US ITER/ORNL. Robert

  10. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US delivers multiple "firsts" for ITER site US delivers multiple "firsts" for ITER site Conductor for toroidal field magnets, drain tanks and electrical components are being delivered to Europe for installation at the ITER site -Lynne Degitz March 19, 2015 Conductor for toroidal field magnets A close-up view of toroidal field production conductor. The conductor delivered in January is approximately 800 meters in length. Photo: US ITER As the international ITER magnetic fusion

  11. On the interplay between inner and outer iterations for a class of iterative methods

    SciTech Connect (OSTI)

    Giladi, E.

    1994-12-31

    Iterative algorithms for solving linear systems of equations often involve the solution of a subproblem at each step. This subproblem is usually another linear system of equations. For example, a preconditioned iteration involves the solution of a preconditioner at each step. In this paper, the author considers algorithms for which the subproblem is also solved iteratively. The subproblem is then said to be solved by {open_quotes}inner iterations{close_quotes} while the term {open_quotes}outer iteration{close_quotes} refers to a step of the basic algorithm. The cost of performing an outer iteration is dominated by the solution of the subproblem, and can be measured by the number of inner iterations. A good measure of the total amount of work needed to solve the original problem to some accuracy c is then, the total number of inner iterations. To lower the amount of work, one can consider solving the subproblems {open_quotes}inexactly{close_quotes} i.e. not to full accuracy. Although this diminishes the cost of solving each subproblem, it usually slows down the convergence of the outer iteration. It is therefore interesting to study the effect of solving each subproblem inexactly on the total amount of work. Specifically, the author considers strategies in which the accuracy to which the inner problem is solved, changes from one outer iteration to the other. The author seeks the `optimal strategy`, that is, the one that yields the lowest possible cost. Here, the author develops a methodology to find the optimal strategy, from the set of slowly varying strategies, for some iterative algorithms. This methodology is applied to the Chebychev iteration and it is shown that for Chebychev iteration, a strategy in which the inner-tolerance remains constant is optimal. The author also estimates this optimal constant. Then generalizations to other iterative procedures are discussed.

  12. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In Jacob's Room at US ITER Fusion Comes to the Secret City Published June 20, 2011 The ... Over 1000 visitors toured the exhibits and learned more about fusion, ITER progress, and ...

  13. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Diagnostics Diagnostics (WBS 1.5.3) Fact Sheet ITER Diagnostics Image Highlighted in pink: US contributions to ITER diagnostics. The US is responsible for 14% of port-based ...

  14. US ITER - Why Fusion?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    PPPL FusEdWeb Educational Outreach: US ITER staff members are available for presentations on fusion energy and the ITER project to technical, civic, community, and student groups. ...

  15. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    your own transportation to and from US ITER. A rental car is suggested for short stays. ... or comments at webmaster@usiter.org. ITER International Department of Energy Office ...

  16. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Photo: US ITER. The first part of the central solenoid winding station is a de-spooler, shown here unwinding material for the mock-up coil. Photo: US ITER . At the heart of the ...

  17. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER ships 30,000 pounds of magnet system hardware to Europe US ITER ships 30,000 pounds of magnet system hardware to Europe An 800-meter length of sample toroidal field ...

  18. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER Major Vendors, Project Director to Speak at FPA Annual Meeting US ITER Major Vendors, Project Director to Speak at FPA Annual Meeting in December Published September 28, ...

  19. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Videos US ITER Moving Forward US ITER Moving Forward (2012) Ned Sauthoff and Susan McGinnis - Fusion Reaction Energy for the Future (2011) Ned Sauthoff and Susan McGinnis - Fusion ...

  20. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER is building one of the world's largest and most powerful electromagnets to energize the ITER tokamak, a device that confines plasma in the shape of a doughnut. The 13 meter ...

  1. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER Project Office Disruption Mitigation Team Leader, Oak Ridge National Laboratory, rasmussnda@ornl.gov | 865-574-1158 News 3D printing yields advantages for US ITER ...

  2. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tokamak Exhaust Processing System (WBS 1.3.2) FactSheet Exhaust Process Image The ITER ... ITER will require the processing of an unprecedented rate of hydrogen isotopes. To ...

  3. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER > US Hardware > Toroidal Field (TF) Magnets Central Solenoid (CS) (WBS 1.1.1) Fact Sheet Central Solenoid Highlighted in pink: The central solenoid, or "backbone" of the ITER ...

  4. US ITER | Jobs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    What were you doing before you came to US ITER? When I was a sophomore at UTK, I began to ... and later bid on the job at ITER where I have been for the last five and a half years. ...

  5. US ITER Moving Forward

    SciTech Connect (OSTI)

    US ITER / ORNL

    2012-01-01

    US ITER Project Manager Ned Sauthoff, joined by Wayne Reiersen, Team Leader Magnet Systems, and Jan Berry, Team Leader Tokamak Cooling System, discuss the U.S.'s role in the ITER international collaboration.

  6. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The maps below will help you find your way to the US ITER Project Office and around ORNL and Oak Ridge. They are all provided in PDF format unless noted. ITER - Oak Ridge Office ...

  7. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    News Service, January 4, 2007 Head of US ITER project named IEEE Fellow ORNL News ... Power IBM press release, July 2, 2007 ITER Selects ANSYS Solutions for Design of ...

  8. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    develop high-performance steel for ITER The Oak Ridger, November 2, 2008 Can ... News Sentinel, July 29, 2008 Fund ITER Now EnergyBiz Magazine, July 21, 2008 ...

  9. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    test bed ring will load ITER transmission lines with up to 6 megawatts New test bed ring will load ITER transmission lines with up to 6 megawatts -Agatha Bardoel Published April ...

  10. US ITER | Jobs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Suzanne Herron US ITER Deputy Project Manager Tell us about your background Suzanne Herron ... What were you doing before you came to US ITER? I have had a variety of experiences in my ...

  11. US ITER | Jobs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Postings Careers in Fusion Science ITER Jobs Home > Jobs > Careers in Fusion Science Learn More About Working at US ITER and Careers in Fusion Science Jan Berry Takes a Different ...

  12. US ITER Moving Forward

    ScienceCinema (OSTI)

    US ITER / ORNL

    2012-03-16

    US ITER Project Manager Ned Sauthoff, joined by Wayne Reiersen, Team Leader Magnet Systems, and Jan Berry, Team Leader Tokamak Cooling System, discuss the U.S.'s role in the ITER international collaboration.

  13. What is ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The project is being designed and built by the ITER partners: China, the European Union, India, Japan, South Korea, the Russia Federation, and the United States. The ITER facility ...

  14. INSIDE: ITER Site Progress

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Industry, Universities and Labs Job Openings Upcoming Events ITER's Central Magnet Requires a Powerful Support Cage Prototypes for the central solenoid support components have been fabricated and are being tested US ITER is building one of the world's largest and most powerful electromagnets to energize the ITER tokamak, a device that confines plasma in the shape of a doughnut. The 13 meter tall central solenoid will be located in the heart of the ITER fusion experiment. In order to maintain

  15. C–IBI: Targeting cumulative coordination within an iterative protocol to derive coarse-grained models of (multi-component) complex fluids

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    de Oliveira, Tiago E.; Netz, Paulo A.; Kremer, Kurt; Junghans, Christoph; Mukherji, Debashish

    2016-05-03

    We present a coarse-graining strategy that we test for aqueous mixtures. The method uses pair-wise cumulative coordination as a target function within an iterative Boltzmann inversion (IBI) like protocol. We name this method coordination iterative Boltzmann inversion (C–IBI). While the underlying coarse-grained model is still structure based and, thus, preserves pair-wise solution structure, our method also reproduces solvation thermodynamics of binary and/or ternary mixtures. In addition, we observe much faster convergence within C–IBI compared to IBI. To validate the robustness, we apply C–IBI to study test cases of solvation thermodynamics of aqueous urea and a triglycine solvation in aqueous urea.

  16. Assessing image quality and dose reduction of a new x-ray computed tomography iterative reconstruction algorithm using model observers

    SciTech Connect (OSTI)

    Tseng, Hsin-Wu Kupinski, Matthew A.; Fan, Jiahua; Sainath, Paavana; Hsieh, Jiang

    2014-07-15

    Purpose: A number of different techniques have been developed to reduce radiation dose in x-ray computed tomography (CT) imaging. In this paper, the authors will compare task-based measures of image quality of CT images reconstructed by two algorithms: conventional filtered back projection (FBP), and a new iterative reconstruction algorithm (IR). Methods: To assess image quality, the authors used the performance of a channelized Hotelling observer acting on reconstructed image slices. The selected channels are dense difference Gaussian channels (DDOG).A body phantom and a head phantom were imaged 50 times at different dose levels to obtain the data needed to assess image quality. The phantoms consisted of uniform backgrounds with low contrast signals embedded at various locations. The tasks the observer model performed included (1) detection of a signal of known location and shape, and (2) detection and localization of a signal of known shape. The employed DDOG channels are based on the response of the human visual system. Performance was assessed using the areas under ROC curves and areas under localization ROC curves. Results: For signal known exactly (SKE) and location unknown/signal shape known tasks with circular signals of different sizes and contrasts, the authors’ task-based measures showed that a FBP equivalent image quality can be achieved at lower dose levels using the IR algorithm. For the SKE case, the range of dose reduction is 50%–67% (head phantom) and 68%–82% (body phantom). For the study of location unknown/signal shape known, the dose reduction range can be reached at 67%–75% for head phantom and 67%–77% for body phantom case. These results suggest that the IR images at lower dose settings can reach the same image quality when compared to full dose conventional FBP images. Conclusions: The work presented provides an objective way to quantitatively assess the image quality of a newly introduced CT IR algorithm. The performance of the

  17. ITER helium ash accumulation

    SciTech Connect (OSTI)

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. . Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  18. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Building the Heartbeat of ITER Building the Heartbeat of ITER Preparing a unique fabrication line for the central solenoid modules -Lynne Degitz September 14, 2015 A partial view of the General Atomics module fabrication line, with two winding station tables visible behind a yellow rail. Photo: GA A partial view of the General Atomics module fabrication line, with two winding station tables visible behind a yellow rail. Photo: GA With winding of the first production module for ITER's central

  19. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Please feel free to contact us with any questions or comments at webmaster@usiter.org. ITER International Department of Energy Office of Science Oak Ridge National Laboratory ...

  20. US ITER | Doing Business

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Please direct any questions, correspondence or submissions to the PPPL Procurement Division. ITER International Department of Energy Office of Science Oak Ridge National Laboratory ...

  1. US ITER | Contact Us

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Staff Directory Staff Directory Lookup Fields Last Name Institution Submit Reset ITER International Department of Energy Office of Science Oak Ridge National Laboratory Princeton ...

  2. US ITER - Why Fusion?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER International Department of Energy Office of Science Oak Ridge National Laboratory Princeton Plasma Physics Laboratory Savannah River National Laboratory Last updated: 0327...

  3. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The Steady-State Electrical Network is an AC power substation and distribution system that supplies electrical power to all ITER conventional systems and facilities. A separate ...

  4. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Life-size Mock-Up Helps R&D Staff Get a Feel for the Scale of ITER Life-size Mock-Up Helps R&D Staff Get a Feel for the Scale of ITER -Agatha Bardoel Published October 7, 2011 A ...

  5. Preconditioned Iterative Solver

    Energy Science and Technology Software Center (OSTI)

    2002-08-01

    AztecOO contains a collection of preconditioned iterative methods for the solution of sparse linear systems of equations. In addition to providing many of the common algebraic preconditioners and basic iterative methods, AztecOO can be easily extended to interact with user-provided preconditioners and matrix operators.

  6. Use of the iterative solution method for coupled finite element and boundary element modeling; Yucca Mountain Site Characterization Project

    SciTech Connect (OSTI)

    Koteras, J.R.

    1993-07-01

    Tunnels buried deep within the earth constitute an important class geomechanics problems. Two numerical techniques used for the analysis of geomechanics problems, the finite element method and the boundary element method, have complementary characteristics for applications to problems of this type. The usefulness of combining these two methods for use as a geomechanics analysis tool has been recognized for some time, and a number of coupling techniques have been proposed. However, not all of them lend themselves to efficient computational implementations for large-scale problems. This report examines a coupling technique that can form the basis for an efficient analysis tool for large scale geomechanics problems through the use of an iterative equation solver.

  7. Current generation by helicons and LH waves in modern tokamaks and reactors FNSF-AT, ITER and DEMO. Scenarios, modeling and antennae

    SciTech Connect (OSTI)

    Vdovin, V.

    2014-02-12

    The Innovative concept and 3D full wave code modeling Off-axis current drive by RF waves in large scale tokamaks, reactors FNSF-AT, ITER and DEMO for steady state operation with high efficiency was proposed [1] to overcome problems well known for LH method [2]. The scheme uses the helicons radiation (fast magnetosonic waves at high (20–40) IC frequency harmonics) at frequencies of 500–1000 MHz, propagating in the outer regions of the plasmas with a rotational transform. It is expected that the current generated by Helicons will help to have regimes with negative magnetic shear and internal transport barrier to ensure stability at high normalized plasma pressure β{sub N} > 3 (the so-called Advanced scenarios) of interest for FNSF and the commercial reactor. Modeling with full wave three-dimensional codes PSTELION and STELEC2 showed flexible control of the current profile in the reactor plasmas of ITER, FNSF-AT and DEMO [2,3], using multiple frequencies, the positions of the antennae and toroidal waves slow down. Also presented are the results of simulations of current generation by helicons in tokamaks DIII-D, T-15MD and JT-60SA [3]. In DEMO and Power Plant antenna is strongly simplified, being some analoge of mirrors based ECRF launcher, as will be shown. For spherical tokamaks the Helicons excitation scheme does not provide efficient Off-axis CD profile flexibility due to strong coupling of helicons with O-mode, also through the boundary conditions in low aspect machines, and intrinsic large amount of trapped electrons, as is shown by STELION modeling for the NSTX tokamak. Brief history of Helicons experimental and modeling exploration in straight plasmas, tokamaks and tokamak based fusion Reactors projects is given, including planned joint DIII-D – Kurchatov Institute experiment on helicons CD [1].

  8. Travel Requirements - ITER (June 2014

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Travel Requirements - ITER (June 2014) Prior to any travel under this subcontract, the ... approval, with a copy to the identified US ITER Project Office Travel Administrative ...

  9. INSIDE: ITER Site Progress

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Industry Monaco/ITER Postdoctoral Fellowship Program Upcoming Events US Researchers Parse Complex Plasma Issues From "Snowballs in Hell" to "Burping the Baby" - by Agatha Bardoel The design, testing, and manufacture of a pellet injection system is one of the key contributions of the United States to ITER. Physicist David Rasmussen serves as the lead for US ITER's fueling team and as a group leader in the Fusion Energy Division at Oak Ridge National Laboratory. He points out

  10. Assessment of the dose reduction potential of a model-based iterative reconstruction algorithm using a task-based performance metrology

    SciTech Connect (OSTI)

    Samei, Ehsan; Richard, Samuel

    2015-01-15

    Purpose: Different computed tomography (CT) reconstruction techniques offer different image quality attributes of resolution and noise, challenging the ability to compare their dose reduction potential against each other. The purpose of this study was to evaluate and compare the task-based imaging performance of CT systems to enable the assessment of the dose performance of a model-based iterative reconstruction (MBIR) to that of an adaptive statistical iterative reconstruction (ASIR) and a filtered back projection (FBP) technique. Methods: The ACR CT phantom (model 464) was imaged across a wide range of mA setting on a 64-slice CT scanner (GE Discovery CT750 HD, Waukesha, WI). Based on previous work, the resolution was evaluated in terms of a task-based modulation transfer function (MTF) using a circular-edge technique and images from the contrast inserts located in the ACR phantom. Noise performance was assessed in terms of the noise-power spectrum (NPS) measured from the uniform section of the phantom. The task-based MTF and NPS were combined with a task function to yield a task-based estimate of imaging performance, the detectability index (d′). The detectability index was computed as a function of dose for two imaging tasks corresponding to the detection of a relatively small and a relatively large feature (1.5 and 25 mm, respectively). The performance of MBIR in terms of the d′ was compared with that of ASIR and FBP to assess its dose reduction potential. Results: Results indicated that MBIR exhibits a variability spatial resolution with respect to object contrast and noise while significantly reducing image noise. The NPS measurements for MBIR indicated a noise texture with a low-pass quality compared to the typical midpass noise found in FBP-based CT images. At comparable dose, the d′ for MBIR was higher than those of FBP and ASIR by at least 61% and 19% for the small feature and the large feature tasks, respectively. Compared to FBP and ASIR, MBIR

  11. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    If you plan to be in the area for an extended time, you might find the accommodations page under the Relocating section to be helpful. ITER International Department of Energy ...

  12. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    To produce the pellets, researchers developed a twin-screw extruder which shapes a ... needed to supply a few seconds of fuel pellets at a time, but the ITER tokamak will ...

  13. US ITER | About

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The ITER TF coils are designed to have a total magnetic energy of 41 gigajoules and a maximum magnetic field of 11.8 tesla. The US is responsible for enough conductor to wind ...

  14. US ITER | Contact Us

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US Key Contact Key Contact Mark Uhran Communications Manager 865-574-8381 ITER International Department of Energy Office of Science Oak Ridge National Laboratory Princeton Plasma Physics Laboratory Savannah River National Laboratory Last updated: 05/21/2013

  15. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fusion diagnostics heat up across the US Fusion diagnostics heat up across the US Teams are developing tools to monitor and control ITER plasma -Lynne Degitz October 22, 2015 ITER, the world's largest tokamak now under construction in France, will have over 60 diagnostic systems installed to enable plasma control, optimize plasma performance, and support machine protection¬. Princeton Plasma Physics Laboratory and Oak Ridge National Laboratory, in collaboration with industry and universities,

  16. INSIDE: ITER Site Progress

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Continued on page 8 INSIDE: ITER Site Progress View from DOE US Systems Update Engaging Industry, Universities and Labs Upcoming Events Disruption Mitigation Researchers Investigate Design Options ITER, the world's first reactor-scale fusion machine, will have a plasma volume more than 10 times that of the next largest tokamak, JET. Plasma disruptions that can occur in a tokamak when the plasma becomes unstable can potentially damage plasma-facing surfaces of the machine. To lessen the impact of

  17. Final Report on ITER Task Agreement 81-08

    SciTech Connect (OSTI)

    Richard L. Moore

    2008-03-01

    As part of an ITER Implementing Task Agreement (ITA) between the ITER US Participant Team (PT) and the ITER International Team (IT), the INL Fusion Safety Program was tasked to provide the ITER IT with upgrades to the fusion version of the MELCOR 1.8.5 code including a beryllium dust oxidation model. The purpose of this model is to allow the ITER IT to investigate hydrogen production from beryllium dust layers on hot surfaces inside the ITER vacuum vessel (VV) during in-vessel loss-of-cooling accidents (LOCAs). Also included in the ITER ITA was a task to construct a RELAP5/ATHENA model of the ITER divertor cooling loop to model the draining of the loop during a large ex-vessel pipe break followed by an in-vessel divertor break and compare the results to a simular MELCOR model developed by the ITER IT. This report, which is the final report for this agreement, documents the completion of the work scope under this ITER TA, designated as TA 81-08.

  18. Iterative software kernels

    SciTech Connect (OSTI)

    Duff, I.

    1994-12-31

    This workshop focuses on kernels for iterative software packages. Specifically, the three speakers discuss various aspects of sparse BLAS kernels. Their topics are: `Current status of user lever sparse BLAS`; Current status of the sparse BLAS toolkit`; and `Adding matrix-matrix and matrix-matrix-matrix multiply to the sparse BLAS toolkit`.

  19. ITER Fusion Energy

    ScienceCinema (OSTI)

    Dr. Norbert Holtkamp

    2010-01-08

    ITER (in Latin ?the way?) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen ? deuterium and tritium ? fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project ? China, the European Union, India, Japan, Korea, Russia and the United States ? represent more than half the world?s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

  20. The ITER Project: International Collaboration to Demonstrate...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The ITER Project: International Collaboration to Demonstrate Nuclear Fusion American Fusion News Category: U.S. ITER Link: The ITER Project: International Collaboration to ...

  1. Nuclear Forensic Inferences Using Iterative Multidimensional Statistics

    SciTech Connect (OSTI)

    Robel, M; Kristo, M J; Heller, M A

    2009-06-09

    Nuclear forensics involves the analysis of interdicted nuclear material for specific material characteristics (referred to as 'signatures') that imply specific geographical locations, production processes, culprit intentions, etc. Predictive signatures rely on expert knowledge of physics, chemistry, and engineering to develop inferences from these material characteristics. Comparative signatures, on the other hand, rely on comparison of the material characteristics of the interdicted sample (the 'questioned sample' in FBI parlance) with those of a set of known samples. In the ideal case, the set of known samples would be a comprehensive nuclear forensics database, a database which does not currently exist. In fact, our ability to analyze interdicted samples and produce an extensive list of precise materials characteristics far exceeds our ability to interpret the results. Therefore, as we seek to develop the extensive databases necessary for nuclear forensics, we must also develop the methods necessary to produce the necessary inferences from comparison of our analytical results with these large, multidimensional sets of data. In the work reported here, we used a large, multidimensional dataset of results from quality control analyses of uranium ore concentrate (UOC, sometimes called 'yellowcake'). We have found that traditional multidimensional techniques, such as principal components analysis (PCA), are especially useful for understanding such datasets and drawing relevant conclusions. In particular, we have developed an iterative partial least squares-discriminant analysis (PLS-DA) procedure that has proven especially adept at identifying the production location of unknown UOC samples. By removing classes which fell far outside the initial decision boundary, and then rebuilding the PLS-DA model, we have consistently produced better and more definitive attributions than with a single pass classification approach. Performance of the iterative PLS-DA method

  2. US Contributions to ITER Project

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Contributions to ITER Project 12715 D etailee * M M atrix * S C S ubcontractor * * D ual C apacity 2

  3. ITER | Princeton Plasma Physics Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER Subscribe to RSS - ITER ITER is a large international fusion experiment aimed at demonstrating the scientific and technological feasibility of fusion energy. ITER (Latin for "the way") will play a critical role advancing the worldwide availability of energy from fusion - the power source of the sun and the stars. To produce practical amounts of fusion power on earth, heavy forms of hydrogen are joined together at high temperature with an accompanying production of heat energy. The

  4. US ITER | Media Corner

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Cryogenic deuterium machine gun corrals edgy plasma Cryogenic deuterium machine gun corrals edgy plasma -Agatha Bardoel Published May 3, 2012 Cryogenic deuterium machine gun Internal image of the three-barrel repeating pneumatic deuterium pellet injector used on DIII-D for pellet ELM pacing experiments. Photo: US ITER/ORNL Using a cryogenic deuterium pellet injector installed on the DIII-D tokamak operated for the Department of Energy Office of Science by General Atomics in San Diego, ORNL

  5. Iterative reconstruction of magnetic induction using Lorentz...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography Title Iterative reconstruction of magnetic induction using Lorentz transmission...

  6. ETR/ITER systems code

    SciTech Connect (OSTI)

    Barr, W.L.; Bathke, C.G.; Brooks, J.N.; Bulmer, R.H.; Busigin, A.; DuBois, P.F.; Fenstermacher, M.E.; Fink, J.; Finn, P.A.; Galambos, J.D.; Gohar, Y.; Gorker, G.E.; Haines, J.R.; Hassanein, A.M.; Hicks, D.R.; Ho, S.K.; Kalsi, S.S.; Kalyanam, K.M.; Kerns, J.A.; Lee, J.D.; Miller, J.R.; Miller, R.L.; Myall, J.O.; Peng, Y-K.M.; Perkins, L.J.; Spampinato, P.T.; Strickler, D.J.; Thomson, S.L.; Wagner, C.E.; Willms, R.S.; Reid, R.L.

    1988-04-01

    A tokamak systems code capable of modeling experimental test reactors has been developed and is described in this document. The code, named TETRA (for Tokamak Engineering Test Reactor Analysis), consists of a series of modules, each describing a tokamak system or component, controlled by an optimizer/driver. This code development was a national effort in that the modules were contributed by members of the fusion community and integrated into a code by the Fusion Engineering Design Center. The code has been checked out on the Cray computers at the National Magnetic Fusion Energy Computing Center and has satisfactorily simulated the Tokamak Ignition/Burn Experimental Reactor II (TIBER) design. A feature of this code is the ability to perform optimization studies through the use of a numerical software package, which iterates prescribed variables to satisfy a set of prescribed equations or constraints. This code will be used to perform sensitivity studies for the proposed International Thermonuclear Experimental Reactor (ITER). 22 figs., 29 tabs.

  7. INSIDE: ITER Site Progress

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    From the Project Manager Awards and Procurement Update Project Highlights 2015 Timeline A Ye a r o f " F i r s t s " Continued on page 3 December 2015 for US Delivery and Fabrication First Nuclear Grade Hardware Delivered The US completed delivery of five drain tanks, fabricated by Joseph Oat Corporation in Camden, New Jersey, for the tokamak cooling water system. The tanks represent the first delivery of nuclear grade hardware to the ITER site. The US team achieved a strong working

  8. US ITER | Why Fusion?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Why Fusion? US Fusion Research Educational Resources Why Fusion? Home > Why Fusion? What is Fusion? Fusion is a key element in long-term US energy plans. ITER will allow scientists to explore the physics of a burning plasma at energy densities close to that of a commercial power plant. This is a critical step towards producing and delivering electricity from fusion to the grid. Nuclear fusion occurs naturally in stars, like our sun. When hydrogen gets hot enough, the process of fusion

  9. SciDAC Center for Simulation of Wave-Plasma Interactions - Iterated Finite-Orbit Monte Carlo Simulations with Full-Wave Fields for Modeling Tokamak ICRF Wave Heating Experiments - Final Report

    SciTech Connect (OSTI)

    Choi, Myunghee; Chan, Vincent S.

    2014-02-28

    This final report describes the work performed under U.S. Department of Energy Cooperative Agreement DE-FC02-08ER54954 for the period April 1, 2011 through March 31, 2013. The goal of this project was to perform iterated finite-orbit Monte Carlo simulations with full-wall fields for modeling tokamak ICRF wave heating experiments. In year 1, the finite-orbit Monte-Carlo code ORBIT-RF and its iteration algorithms with the full-wave code AORSA were improved to enable systematical study of the factors responsible for the discrepancy in the simulated and the measured fast-ion FIDA signals in the DIII-D and NSTX ICRF fast-wave (FW) experiments. In year 2, ORBIT-RF was coupled to the TORIC full-wave code for a comparative study of ORBIT-RF/TORIC and ORBIT-RF/AORSA results in FW experiments.

  10. Technical Proposal Disclosure Policy - ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proposal Disclosure Policy - ITER Pursuant to this solicitation, UT-Battelle will treat confidential proposal information as such and will disclose such information on a need to ...

  11. Pore scale modeling of reactive transport involved in geologic CO2 sequestration

    SciTech Connect (OSTI)

    Kang, Qinjin; Lichtner, Peter C; Viswanathan, Hari S; Abdel-fattah, Amr I

    2009-01-01

    We apply a multi-component reactive transport lattice Boltzmann model developed in previolls studies to modeling the injection of a C02 saturated brine into various porous media structures at temperature T=25 and 80 C. The porous media are originally consisted of calcite. A chemical system consisting of Na+, Ca2+, Mg2+, H+, CO2(aq), and CI-is considered. The fluid flow, advection and diHusion of aqueous species, homogeneous reactions occurring in the bulk fluid, as weB as the dissolution of calcite and precipitation of dolomite are simulated at the pore scale. The effects of porous media structure on reactive transport are investigated. The results are compared with continuum scale modeling and the agreement and discrepancy are discussed. This work may shed some light on the fundamental physics occurring at the pore scale for reactive transport involved in geologic C02 sequestration.

  12. BBC Video Looks at ITER | Princeton Plasma Physics Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    BBC Video Looks at ITER American Fusion News Category: U.S. ITER Link: BBC Video Looks at ITER

  13. Model studies in cytochrome P-450 mediated toxicity of halogenated compounds: radical processes involving iron porphyrins

    SciTech Connect (OSTI)

    Brault, D.

    1985-12-01

    Haloalkane toxicity originates from attack on biological targets by reactive intermediates derived from haloalkane metabolism by a hemoprotein, cytochrome P-450. Carbon-centered radicals and their peroxylderivatives are most likely involved. The reactions of iron porphyrin - a model for cytochrome P-450 - with various carbon-centered and peroxyl radicals generated by pulse radiolysis are examined. Competition between iron porphyrin and unsaturated fatty acids for attack by peroxyl radicals is pointed out. These kinetic data are used to derive a model for toxicity of haloalkanes with particular attention to carbon tetrachloride and halothane. The importance of local oxygen concentration and structural arrangement of fatty acids around cytochrome P-450 is emphasized. 56 references.

  14. ITER Diagnostic First Wal

    SciTech Connect (OSTI)

    G. Douglas Loesser, et. al.

    2012-09-21

    The ITER Diagnostic Division is responsible for designing and procuring the First Wall Blankets that are mounted on the vacuum vessel port plugs at both the upper and equatorial levels This paper will discuss the effects of the diagnostic aperture shape and configuration on the coolant circuit design. The DFW design is driven in large part by the need to conform the coolant arrangement to a wide variety of diagnostic apertures combined with the more severe heating conditions at the surface facing the plasma, the first wall. At the first wall, a radiant heat flux of 35W/cm2 combines with approximate peak volumetric heating rates of 8W/cm3 (equatorial ports) and 5W/cm3 (upper ports). Here at the FW, a fast thermal response is desirable and leads to a thin element between the heat flux and coolant. This requirement is opposed by the wish for a thicker FW element to accommodate surface erosion and other off-normal plasma events.

  15. Voila: A visual object-oriented iterative linear algebra problem solving environment

    SciTech Connect (OSTI)

    Edwards, H.C.; Hayes, L.J.

    1994-12-31

    Application of iterative methods to solve a large linear system of equations currently involves writing a program which calls iterative method subprograms from a large software package. These subprograms have complex interfaces which are difficult to use and even more difficult to program. A problem solving environment specifically tailored to the development and application of iterative methods is needed. This need will be fulfilled by Voila, a problem solving environment which provides a visual programming interface to object-oriented iterative linear algebra kernels. Voila will provide several quantum improvements over current iterative method problem solving environments. First, programming and applying iterative methods is considerably simplified through Voila`s visual programming interface. Second, iterative method algorithm implementations are independent of any particular sparse matrix data structure through Voila`s object-oriented kernels. Third, the compile-link-debug process is eliminated as Voila operates as an interpreter.

  16. US ITER toroidal field coil conductor...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER toroidal field coil conductor production requires miles of niobium-tin superconducting wire. Photo: Oxford Superconducting Technology Continued on page 6 INSIDE: ITER Site ...

  17. Identification of Export Control Classification Number - ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Export Control Classification Number - ITER (April 2012) As the "Shipper of Record" ... be shipped from the United States to the ITER International Organization in Cadarache, ...

  18. Gamma ray spectrometer for ITER

    SciTech Connect (OSTI)

    Gin, D.; Chugunov, I.; Shevelev, A.; Khilkevitch, E.; Doinikov, D.; Naidenov, V.; Pasternak, A.; Polunovsky, I.; Kiptily, V.

    2014-08-21

    Gamma diagnostics is considered to be primary for the confined α-particles and runaway electrons measurements on ITER. The gamma spectrometer will be embedded into a neutron dump of the ITER Neutral Particle Analyzer diagnostic complex. It will supplement NPA measurements on the fuel isotope ratio and confined alphas/fast ions. In this paper an update on ITER gamma spectrometer developments is given. A new geometry of the system is described and detailed analysis of expected signals for the spectrometer is presented.

  19. Iterative Reconstruction of Coded Source Neutron Radiographs

    SciTech Connect (OSTI)

    Santos-Villalobos, Hector J; Bingham, Philip R; Gregor, Jens

    2012-01-01

    Use of a coded source facilitates high-resolution neutron imaging but requires that the radiographic data be deconvolved. In this paper, we compare direct deconvolution with two different iterative algorithms, namely, one based on direct deconvolution embedded in an MLE-like framework and one based on a geometric model of the neutron beam and a least squares formulation of the inverse imaging problem.

  20. In-vessel tritium retention and removal in ITER

    SciTech Connect (OSTI)

    Federici, G.; Anderl, R.A.; Andrew, P.

    1998-06-01

    The International Thermonuclear Experimental Reactor (ITER) is envisioned to be the next major step in the world`s fusion program from the present generation of tokamaks and is designed to study fusion plasmas with a reactor relevant range of plasma parameters. During normal operation, it is expected that a fraction of the unburned tritium, that is used to routinely fuel the discharge, will be retained together with deuterium on the surfaces and in the bulk of the plasma facing materials (PFMs) surrounding the core and divertor plasma. The understanding of he basic retention mechanisms (physical and chemical) involved and their dependence upon plasma parameters and other relevant operation conditions is necessary for the accurate prediction of the amount of tritium retained at any given time in the ITER torus. Accurate estimates are essential to assess the radiological hazards associated with routine operation and with potential accident scenarios which may lead to mobilization of tritium that is not tenaciously held. Estimates are needed to establish the detritiation requirements for coolant water, to determine the plasma fueling and tritium supply requirements, and to establish the needed frequency and the procedures for tritium recovery and clean-up. The organization of this paper is as follows. Section 2 provides an overview of the design and operating conditions of the main components which define the plasma boundary of ITER. Section 3 reviews the erosion database and the results of recent relevant experiments conducted both in laboratory facilities and in tokamaks. These data provide the experimental basis and serve as an important benchmark for both model development (discussed in Section 4) and calculations (discussed in Section 5) that are required to predict tritium inventory build-up in ITER. Section 6 emphasizes the need to develop and test methods to remove the tritium from the codeposited C-based films and reviews the status and the prospects of the

  1. Recent ADI iteration analysis and results

    SciTech Connect (OSTI)

    Wachspress, E.L.

    1994-12-31

    Some recent ADI iteration analysis and results are discussed. Discovery that the Lyapunov and Sylvester matrix equations are model ADI problems stimulated much research on ADI iteration with complex spectra. The ADI rational Chebyshev analysis parallels the classical linear Chebyshev theory. Two distinct approaches have been applied to these problems. First, parameters which were optimal for real spectra were shown to be nearly optimal for certain families of complex spectra. In the linear case these were spectra bounded by ellipses in the complex plane. In the ADI rational case these were spectra bounded by {open_quotes}elliptic-function regions{close_quotes}. The logarithms of the latter appear like ellipses, and the logarithms of the optimal ADI parameters for these regions are similar to the optimal parameters for linear Chebyshev approximation over superimposed ellipses. W.B. Jordan`s bilinear transformation of real variables to reduce the two-variable problem to one variable was generalized into the complex plane. This was needed for ADI iterative solution of the Sylvester equation.

  2. ODE System Solver W. Krylov Iteration & Rootfinding

    Energy Science and Technology Software Center (OSTI)

    1991-09-09

    LSODKR is a new initial value ODE solver for stiff and nonstiff systems. It is a variant of the LSODPK and LSODE solvers, intended mainly for large stiff systems. The main differences between LSODKR and LSODE are the following: (a) for stiff systems, LSODKR uses a corrector iteration composed of Newton iteration and one of four preconditioned Krylov subspace iteration methods. The user must supply routines for the preconditioning operations, (b) Within the corrector iteration,more » LSODKR does automatic switching between functional (fixpoint) iteration and modified Newton iteration, (c) LSODKR includes the ability to find roots of given functions of the solution during the integration.« less

  3. ODE System Solver W. Krylov Iteration & Rootfinding

    Energy Science and Technology Software Center (OSTI)

    1991-09-09

    LSODKR is a new initial value ODE solver for stiff and nonstiff systems. It is a variant of the LSODPK and LSODE solvers, intended mainly for large stiff systems. The main differences between LSODKR and LSODE are the following: (a) for stiff systems, LSODKR uses a corrector iteration composed of Newton iteration and one of four preconditioned Krylov subspace iteration methods. The user must supply routines for the preconditioning operations, (b) Within the corrector iteration,moreLSODKR does automatic switching between functional (fixpoint) iteration and modified Newton iteration, (c) LSODKR includes the ability to find roots of given functions of the solution during the integration.less

  4. Energetic ions in ITER plasmas

    SciTech Connect (OSTI)

    Pinches, S. D.; Chapman, I. T.; Sharapov, S. E.; Lauber, Ph. W.; Oliver, H. J. C.; Shinohara, K.; Tani, K.

    2015-02-15

    This paper discusses the behaviour and consequences of the expected populations of energetic ions in ITER plasmas. It begins with a careful analytic and numerical consideration of the stability of Alfvén Eigenmodes in the ITER 15 MA baseline scenario. The stability threshold is determined by balancing the energetic ion drive against the dominant damping mechanisms and it is found that only in the outer half of the plasma (r/a>0.5) can the fast ions overcome the thermal ion Landau damping. This is in spite of the reduced numbers of alpha-particles and beam ions in this region but means that any Alfvén Eigenmode-induced redistribution is not expected to influence the fusion burn process. The influence of energetic ions upon the main global MHD phenomena expected in ITER's primary operating scenarios, including sawteeth, neoclassical tearing modes and Resistive Wall Modes, is also reviewed. Fast ion losses due to the non-axisymmetric fields arising from the finite number of toroidal field coils, the inclusion of ferromagnetic inserts, the presence of test blanket modules containing ferromagnetic material, and the fields created by the Edge Localised Mode (ELM) control coils in ITER are discussed. The greatest losses and associated heat loads onto the plasma facing components arise due to the use of the ELM control coils and come from neutral beam ions that are ionised in the plasma edge.

  5. Neutronics at Wisconsin, ORNL advances ITER shielding and internationa...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Neutronics at Wisconsin, ORNL advances ITER shielding and international collaboration American Fusion News Category: U.S. ITER Link: Neutronics at Wisconsin, ORNL advances ITER ...

  6. ITER movie created by Oak Ridge National Laboratory, National...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ITER movie created by Oak Ridge National Laboratory, National Center for Computational Sciences American Fusion News Category: U.S. ITER Link: ITER movie created by Oak Ridge ...

  7. COLLOQUIUM: ITER and its Diagnostics - Rising to the Challenge...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MBG Auditorium COLLOQUIUM: ITER and its Diagnostics - Rising to the Challenge Dr. Mike Walsh ITER The ITER project is now well underway with many teams completing various aspects ...

  8. GENERAL CONDITIONS FOR ITER ORGANIZATION SERVICE CONTRACTS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ......... 8 Article 10. Payment ......The ITER Organization shall make no payment for the period when the Contractor's to be ...

  9. Power Radiated from ITER and CIT by Impurities

    DOE R&D Accomplishments [OSTI]

    Cummings, J.; Cohen, S. A.; Hulse, R.; Post, D. E.; Redi, M. H.; Perkins, J.

    1990-07-01

    The MIST code has been used to model impurity radiation from the edge and core plasmas in ITER and CIT. A broad range of parameters have been varied, including Z{sub eff}, impurity species, impurity transport coefficients, and plasma temperature and density profiles, especially at the edge. For a set of these parameters representative of the baseline ITER ignition scenario, it is seen that impurity radiation, which is produced in roughly equal amounts by the edge and core regions, can make a major improvement in divertor operation without compromising core energy confinement. Scalings of impurity radiation with atomic number and machine size are also discussed.

  10. The community environmental monitoring program: a model for stakeholder involvement in environmental monitoring

    SciTech Connect (OSTI)

    Hartwell, William T.; Shafer, David S.

    2007-07-01

    Since 1981, the Community Environmental Monitoring Program (CEMP) has involved stakeholders directly in its daily operation and data collection, as well as in dissemination of information on radiological surveillance in communities surrounding the Nevada Test Site (NTS), the primary location where the United States (US) conducted nuclear testing until 1992. The CEMP is funded by the US Department of Energy's National Nuclear Security Administration, and is administered by the Desert Research Institute (DRI) of the Nevada System of Higher Education. The CEMP provides training workshops for stakeholders involved in the program, and educational outreach to address public concerns about health risk and environmental impacts from past and ongoing NTS activities. The network includes 29 monitoring stations located across an approximately 160,000 km{sup 2} area of Nevada, Utah and California in the southwestern US. The principal radiological instruments are pressurized ion chambers for measuring gamma radiation, and particulate air samplers, primarily for alpha/beta detection. Stations also employ a full suite of meteorological instruments, allowing for improved interpretation of the effects of meteorological events on background radiation levels. Station sensors are wired to state-of-the-art data-loggers that are capable of several weeks of on-site data storage, and that work in tandem with a communications system that integrates DSL and wireless internet, land line and cellular phone, and satellite technologies for data transfer. Data are managed through a platform maintained by the Western Regional Climate Center (WRCC) that DRI operates for the U.S. National Oceanic and Atmospheric Administration. The WRCC platform allows for near real-time upload and display of current monitoring information in tabular and graphical formats on a public web site. Archival data for each station are also available on-line, providing the ability to perform trending analyses or calculate

  11. Electromagnetic analysis of forces and torques on the ITER shield modules due to plasma disruption.

    SciTech Connect (OSTI)

    Kotulski, Joseph Daniel; Coats, Rebecca Sue; Pasik, Michael Francis; Ulrickson, Michael Andrew

    2009-06-01

    An electromagnetic analysis is performed on the ITER shield modules under different plasma disruption scenarios using the OPERA-3d software. The modeling procedure is explained, electromagnetic torques are presented, and results of the modeling are discussed.

  12. ITER Port Interspace Pressure Calculations

    SciTech Connect (OSTI)

    Carbajo, Juan J; Van Hove, Walter A

    2016-01-01

    The ITER Vacuum Vessel (VV) is equipped with 54 access ports. Each of these ports has an opening in the bioshield that communicates with a dedicated port cell. During Tokamak operation, the bioshield opening must be closed with a concrete plug to shield the radiation coming from the plasma. This port plug separates the port cell into a Port Interspace (between VV closure lid and Port Plug) on the inner side and the Port Cell on the outer side. This paper presents calculations of pressures and temperatures in the ITER (Ref. 1) Port Interspace after a double-ended guillotine break (DEGB) of a pipe of the Tokamak Cooling Water System (TCWS) with high temperature water. It is assumed that this DEGB occurs during the worst possible conditions, which are during water baking operation, with water at a temperature of 523 K (250 C) and at a pressure of 4.4 MPa. These conditions are more severe than during normal Tokamak operation, with the water at 398 K (125 C) and 2 MPa. Two computer codes are employed in these calculations: RELAP5-3D Version 4.2.1 (Ref. 2) to calculate the blowdown releases from the pipe break, and MELCOR, Version 1.8.6 (Ref. 3) to calculate the pressures and temperatures in the Port Interspace. A sensitivity study has been performed to optimize some flow areas.

  13. Preconditioned iterations to calculate extreme eigenvalues

    SciTech Connect (OSTI)

    Brand, C.W.; Petrova, S.

    1994-12-31

    Common iterative algorithms to calculate a few extreme eigenvalues of a large, sparse matrix are Lanczos methods or power iterations. They converge at a rate proportional to the separation of the extreme eigenvalues from the rest of the spectrum. Appropriate preconditioning improves the separation of the eigenvalues. Davidson`s method and its generalizations exploit this fact. The authors examine a preconditioned iteration that resembles a truncated version of Davidson`s method with a different preconditioning strategy.

  14. Identification of Export Control Classification Number - ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of Export Control Classification Number - ITER (April 2012) As the "Shipper of Record" please provide the appropriate Export Control Classification Number (ECCN) for the products (equipment, components and/or materials) and if applicable the nonproprietary associated installation/maintenance documentation that will be shipped from the United States to the ITER International Organization in Cadarache, France or to ITER Members worldwide on behalf of the Company. In rare instances an

  15. French landmark decree authorizes ITER construction | Princeton...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Members of the ITER Organization include China, India, Japan, Russia and South Korea, in addition to the United States and the European Union. Contact Info PPPL Office of ...

  16. Iterative reconstruction of magnetic induction using Lorentz...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    induction of a nanostructure. This allows for implementing the reconstruction as a linear algebra problem such that various iterative algebraic reconstruction methods can be...

  17. Simulations of plasma behavior during pellet injection in ITER

    SciTech Connect (OSTI)

    Klaywittaphat, P. Onjun, T.

    2012-06-15

    Plasma behavior during pellet injection in ITER is investigated using a 1.5D BALDUR integrated predictive modeling code. In these simulations, the pellet ablation is described using the neutral gas shielding (NGS) model developed by Parks and Turnbull [Phys. Fluids 21, 1735 (1978)]. The NGS pellet ablation model that includes the {nabla}B drift effect is coupled with a plasma core transport model, which is a combination of an MMM95 anomalous transport model and an NCLASS neoclassical transport model. The combination of core transport models, together with pellet model, is used to simulate the time evolution of plasma current, ion and electron temperatures, and density profiles for ITER standard type-I ELMy H-mode discharges during the pellet injection. It is found that the injection of pellet can result in either enhancement or degradation of plasma performance. The {nabla}B drift effect on the pellet deposition is very strong in ITER. The plasma density with high field side pellets, which favorable with the {nabla}B drift effect, is much higher and pellet can penetrate much deeper than that with low field side pellets.

  18. Research at ITER towards DEMO: Specific reactor diagnostic studies to be carried out on ITER

    SciTech Connect (OSTI)

    Krasilnikov, A. V.; Kaschuck, Y. A.; Vershkov, V. A.; Petrov, A. A.; Petrov, V. G.; Tugarinov, S. N.

    2014-08-21

    In ITER diagnostics will operate in the very hard radiation environment of fusion reactor. Extensive technology studies are carried out during development of the ITER diagnostics and procedures of their calibration and remote handling. Results of these studies and practical application of the developed diagnostics on ITER will provide the direct input to DEMO diagnostic development. The list of DEMO measurement requirements and diagnostics will be determined during ITER experiments on the bases of ITER plasma physics results and success of particular diagnostic application in reactor-like ITER plasma. Majority of ITER diagnostic already passed the conceptual design phase and represent the state of the art in fusion plasma diagnostic development. The number of related to DEMO results of ITER diagnostic studies such as design and prototype manufacture of: neutron and γ–ray diagnostics, neutral particle analyzers, optical spectroscopy including first mirror protection and cleaning technics, reflectometry, refractometry, tritium retention measurements etc. are discussed.

  19. Models Datasets

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    iteration by iteration. RevSim is an Excel 2010 based model. Much of the logic is VBA code (Visual Basic for Applications); the user does not need to know VBA to run the...

  20. Genome-Wide Identification and 3D Modeling of Proteins involved in DNA Damage Recognition and Repair (Final Report)

    SciTech Connect (OSTI)

    Ruben A. Abagyan, PhD

    2004-04-15

    OAK-B135 DNA Damage Recognition and Repair (DDR and R) proteins play a critical role in cellular responses to low-dose radiation and are associated with cancer. the authors have performed a systematic, genome-wide computational analysis of genomic data for human genes involved in the DDR and R process. The significant achievements of this project include: (1) Construction of the computational pipeline for searching DDR and R genes, building and validation of 3D models of proteins involved in DDR and R; (2) Functional and structural annotation of the 3D models and generation of comprehensive lists of suggested knock-out mutations; (3) Important improvement of macromolecular docking technology and its application to predict the DNA-Protein complex conformation; (4) Development of a new algorithm for improved analysis of high-density oligonucleotide arrays for gene expression profiling; (5) Construction and maintenance of the DNA Damage Recognition and Repair Database; and (6) Producing 14 research papers (10 published and 4 in preparation).

  1. Genome-Wide Identification and 3D Modeling of Proteins involved in DNA Damage Recognition and Repair (Final Report)

    SciTech Connect (OSTI)

    Abagyan, Ruben; An, Jianghong

    2005-08-12

    DNA Damage Recognition and Repair (DDR&R) proteins play a critical role in cellular responses to low-dose radiation and are associated with cancer. We have performed a systematic, genome-wide computational analysis of genomic data for human genes involved in the DDR&R process. The significant achievements of this project include: 1) Construction of the computational pipeline for searching DDR&R genes, building and validation of 3D models of proteins involved in DDR&R; 2) Functional and structural annotation of the 3D models and generation of comprehensive lists of suggested knock-out mutations; and the development of a method to predict the effects of mutations. Large scale testing of technology to identify novel small binding pockets in protein structures leading to new DDRR inhibitor strategies 3) Improvements of macromolecular docking technology (see the CAPRI 1-3 and 4-5 results) 4) Development of a new algorithm for improved analysis of high-density oligonucleotide arrays for gene expression profiling; 5) Construction and maintenance of the DNA Damage Recognition and Repair Database; 6) Producing 15 research papers (12 published and 3 in preparation).

  2. Microsoft Word - ex1b-ITER-mar07.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    B - Patent Rights - Acquisition by the Government - ITER UT-B Contracts Div March 2007 Page 1 of 6 ex1b-ITER-mar07.doc Exhibit 1B ITER Ref: DEAR 952.227-13 PATENT RIGHTS - ...

  3. ITER Generic Diagnostic Upper Port Plug Nuclear Heating and Personnel Dose Rate Assesment

    SciTech Connect (OSTI)

    Russell E. Feder and Mahmoud Z. Youssef

    2009-01-28

    Neutronics analysis to find nuclear heating rates and personnel dose rates were conducted in support of the integration of diagnostics in to the ITER Upper Port Plugs. Simplified shielding models of the Visible-Infrared diagnostic and of a large aperture diagnostic were incorporated in to the ITER global CAD model. Results for these systems are representative of typical designs with maximum shielding and a small aperture (Vis-IR) and minimal shielding with a large aperture. The neutronics discrete-ordinates code ATTILA and SEVERIAN (the ATTILA parallel processing version) was used. Material properties and the 500 MW D-T volume source were taken from the ITER Brand Model MCNP benchmark model. A biased quadrature set equivelant to Sn=32 and a scattering degree of Pn=3 were used along with a 46-neutron and 21-gamma FENDL energy subgrouping. Total nuclear heating (neutron plug gamma heating) in the upper port plugs ranged between 380 and 350 kW for the Vis-IR and Large Aperture cases. The Large Aperture model exhibited lower total heating but much higher peak volumetric heating on the upper port plug structure. Personnel dose rates are calculated in a three step process involving a neutron-only transport calculation, the generation of activation volume sources at pre-defined time steps and finally gamma transport analyses are run for selected time steps. ANSI-ANS 6.1.1 1977 Flux-to-Dose conversion factors were used. Dose rates were evaluated for 1 full year of 500 MW DT operation which is comprised of 3000 1800-second pulses. After one year the machine is shut down for maintenance and personnel are permitted to access the diagnostic interspace after 2-weeks if dose rates are below 100 ?Sv/hr. Dose rates in the Visible-IR diagnostic model after one day of shutdown were 130 ?Sv/hr but fell below the limit to 90 ?Sv/hr 2-weeks later. The Large Aperture style shielding model exhibited higher and more persistent dose rates. After 1-day the dose rate was 230 ?Sv/hr but

  4. ITER Ion Cyclotron Heating and Fueling Systems

    SciTech Connect (OSTI)

    Rasmussen, D.A.; Baylor, L.R.; Combs, S.K.; Fredd, E.; Goulding, R.H.; Hosea, J.; Swain, D.W.

    2005-04-15

    The ITER burning plasma and advanced operating regimes require robust and reliable heating and current drive and fueling systems. The ITER design documents describe the requirements and reference designs for the ion cyclotron and pellet fueling systems. Development and testing programs are required to optimize, validate and qualify these systems for installation on ITER.The ITER ion cyclotron system offers significant technology challenges. The antenna must operate in a nuclear environment and withstand heat loads and disruption forces beyond present-day designs. It must operate for long pulse lengths and be highly reliable, delivering power to a plasma load with properties that will change throughout the discharge. The ITER ion cyclotron system consists of one eight-strap antenna, eight rf sources (20 MW, 35-65 MHz), associated high-voltage DC power supplies, transmission lines and matching and decoupling components.The ITER fueling system consists of a gas injection system and multiple pellet injectors for edge fueling and deep core fueling. Pellet injection will be the primary ITER fuel delivery system. The fueling requirements will require significant extensions in pellet injector pulse length ({approx}3000 s), throughput (400 torr-L/s,) and reliability. The proposed design is based on a centrifuge accelerator fed by a continuous screw extruder. Inner wall pellet injection with the use of curved guide tubes will be utilized for deep fueling.

  5. PPPL's Hawryluk Named ITER Deputy Director-General | Princeton...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    PPPL's Hawryluk Named ITER Deputy Director-General By Patti Wieser March 8, 2011 Tweet ... director-general of the ITER Organization and director of its administration department. ...

  6. Iterative solution of Hermite boundary integral equations (Journal...

    Office of Scientific and Technical Information (OSTI)

    Iterative solution of Hermite boundary integral equations Citation Details In-Document Search Title: Iterative solution of Hermite boundary integral equations An efficient ...

  7. Looking northeast over the ITER construction site

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Looking northeast over the ITER construction site. A power shovel removes the first of some 230,000 cubic meters from the Tokamak Pit. Operations and Safety on the ITER Platform are being carefully coordinated by the Engage Consortium and the French company APAVE. Bulldozers and scrapers are busy leveling the 14,000 square-meter area that will host the huge PF Coils Assembly Building. Welcome to the first U.S. ITER newsletter. We have prepared this publication as part of our effort to better

  8. Alfven Eigenmode Stability with Beams in ITER-like Plasma

    SciTech Connect (OSTI)

    N.N. Gorelenkov; H.L. Berk; R.V. Budny

    2004-07-16

    Toroidicity Alfven Eigenmodes (TAE) in ITER can be driven unstable by two groups of energetic particles, the 3.5 MeV {alpha}-particle fusion products and the tangentially injected 1MeV beam ions. Stability conditions are established using the perturbative NOVA/NOVA-K codes. A quasi-linear diffusion model is then used to assess the induced redistribution of energetic particles.

  9. Nuclear modules of ITER tokamak systems code

    SciTech Connect (OSTI)

    Gohar, Y.; Baker, C.; Brooks, J.; Finn, P.; Hassanein, A.; Willms, S.; Barr, W.; Bushigin, A.; Kalyanam, K.M.; Haines, J.

    1987-10-01

    Nuclear modules were developed to model various reactor components in the ITER systems code. Several design options and cost algorithms are included for each component. The first wall, blanket and shield modules calculate the beryllium zone thickness, the disruptions results, the nuclear responses in different components including the toroidal field coils. Tungsten shield/water coolant/steel structure and steel shield/water coolant are the shield options for the inboard and outboard sections of the reactor. Lithium nitrate dissolved in the water coolant with a variable beryllium zone thickness in the outboard section of the reactor provides the tritium breeding capability. The reactor vault module defines the thickness of the reactor wall and the roof based on the dose equivalent during operation including skyshine contribution. The impurity control module provides the design parameters for the divertor including plate design, heat load, erosion rate, tritium permeation through the plate material to the coolant, plasma contamination by sputtered impurities, and plate lifetime. Several materials: Be, C, V, Mo, and W can be used for the divertor plate to cover a range of plasma edge temperatures. The tritium module calculates tritium and deuterium flow rates for the reactor plant. The tritium inventory in the fuelers, neutral beams, vacuum pumps, impurity control, first wall, and blanket is calculated. Tritium requirements are provided for different operating conditions. The nuclear models are summarized in this paper including the different design options and key analyses of each module. 39 refs., 3 tabs.

  10. Evaluating iterative reconstruction performance in computed tomography

    SciTech Connect (OSTI)

    Chen, Baiyu Solomon, Justin; Ramirez Giraldo, Juan Carlos; Samei, Ehsan

    2014-12-15

    Purpose: Iterative reconstruction (IR) offers notable advantages in computed tomography (CT). However, its performance characterization is complicated by its potentially nonlinear behavior, impacting performance in terms of specific tasks. This study aimed to evaluate the performance of IR with both task-specific and task-generic strategies. Methods: The performance of IR in CT was mathematically assessed with an observer model that predicted the detection accuracy in terms of the detectability index (d′). d′ was calculated based on the properties of the image noise and resolution, the observer, and the detection task. The characterizations of image noise and resolution were extended to accommodate the nonlinearity of IR. A library of tasks was mathematically modeled at a range of sizes (radius 1–4 mm), contrast levels (10–100 HU), and edge profiles (sharp and soft). Unique d′ values were calculated for each task with respect to five radiation exposure levels (volume CT dose index, CTDI{sub vol}: 3.4–64.8 mGy) and four reconstruction algorithms (filtered backprojection reconstruction, FBP; iterative reconstruction in imaging space, IRIS; and sinogram affirmed iterative reconstruction with strengths of 3 and 5, SAFIRE3 and SAFIRE5; all provided by Siemens Healthcare, Forchheim, Germany). The d′ values were translated into the areas under the receiver operating characteristic curve (AUC) to represent human observer performance. For each task and reconstruction algorithm, a threshold dose was derived as the minimum dose required to achieve a threshold AUC of 0.9. A task-specific dose reduction potential of IR was calculated as the difference between the threshold doses for IR and FBP. A task-generic comparison was further made between IR and FBP in terms of the percent of all tasks yielding an AUC higher than the threshold. Results: IR required less dose than FBP to achieve the threshold AUC. In general, SAFIRE5 showed the most significant dose reduction

  11. Anderson Acceleration for Fixed-Point Iterations

    SciTech Connect (OSTI)

    Walker, Homer F.

    2015-08-31

    The purpose of this grant was to support research on acceleration methods for fixed-point iterations, with applications to computational frameworks and simulation problems that are of interest to DOE.

  12. Ewald Summation Approach to Potential Models of Aqueous Electrolytes Involving Gaussian Charges and Induced Dipoles: Formal and Simulation Results

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-11-01

    We present a detailed derivation of the complete set of expressions required for the implementation of an Ewald summation approach to handle the long-range electrostatic interactions of polar and ionic model systems involving Gaussian charges and induced dipole moments with a particular application to the isobaricisothermal molecular dynamics simulation of our Gaussian Charge Polarizable (GCP) water model and its extension to aqueous electrolytes solutions. The set comprises the individual components of the potential energy, electrostatic potential, electrostatic field and gradient, the electrostatic force and the corresponding virial. Moreover, we show how the derived expressions converge to known point-based electrostatic counterpartsmore » when the parameters, defining the Gaussian charge and induced-dipole distributions, are extrapolated to their limiting point values. Finally, we illustrate the Ewald implementation against the current reaction field approach by isothermal-isobaric molecular dynamics of ambient GCP water for which we compared the outcomes of the thermodynamic, microstructural, and polarization behavior.« less

  13. Novel aspects of plasma control in ITER

    SciTech Connect (OSTI)

    Humphreys, D.; Jackson, G.; Walker, M.; Welander, A.; Ambrosino, G.; Pironti, A.; Felici, F.; Kallenbach, A.; Raupp, G.; Treutterer, W.; Kolemen, E.; Lister, J.; Sauter, O.; Moreau, D.; Schuster, E.

    2015-02-15

    ITER plasma control design solutions and performance requirements are strongly driven by its nuclear mission, aggressive commissioning constraints, and limited number of operational discharges. In addition, high plasma energy content, heat fluxes, neutron fluxes, and very long pulse operation place novel demands on control performance in many areas ranging from plasma boundary and divertor regulation to plasma kinetics and stability control. Both commissioning and experimental operations schedules provide limited time for tuning of control algorithms relative to operating devices. Although many aspects of the control solutions required by ITER have been well-demonstrated in present devices and even designed satisfactorily for ITER application, many elements unique to ITER including various crucial integration issues are presently under development. We describe selected novel aspects of plasma control in ITER, identifying unique parts of the control problem and highlighting some key areas of research remaining. Novel control areas described include control physics understanding (e.g., current profile regulation, tearing mode (TM) suppression), control mathematics (e.g., algorithmic and simulation approaches to high confidence robust performance), and integration solutions (e.g., methods for management of highly subscribed control resources). We identify unique aspects of the ITER TM suppression scheme, which will pulse gyrotrons to drive current within a magnetic island, and turn the drive off following suppression in order to minimize use of auxiliary power and maximize fusion gain. The potential role of active current profile control and approaches to design in ITER are discussed. Issues and approaches to fault handling algorithms are described, along with novel aspects of actuator sharing in ITER.

  14. Development of the Butt Joint for the ITER Central Solenoid

    SciTech Connect (OSTI)

    Martovetsky, N N

    2006-08-23

    The ITER Central Solenoid (CS) requires compact and reliable joints for its Cable-in-Conduit Conductor (CICC). The baseline design is a diffusion bonded butt joint. In such a joint the mating cables are compacted to a very low void fraction in a copper sleeve and then heat treated. After the heat treatment the ends are cut, polished and aligned against each other and then diffusion bonded under high compression in a vacuum chamber at 750 C. The jacket is then welded on the conductor to complete the joint, which remarkably does not require more room than a regular conductor. This joint design is based on a proven concept developed for the ITER CS Model Coil that was successfully tested in the previous R&D phase.

  15. An iterative learning controller for nonholonomic mobile robots

    SciTech Connect (OSTI)

    Oriolo, G.; Panzieri, S.; Ulivi, G.

    1998-09-01

    The authors present an iterative learning controller that applies to nonholonomic mobile robots, as well as other systems that can be put in chained form. The learning algorithm exploits the fact that chained-form. The learning algorithm exploits the fact that chained-form systems are linear under piecewise-constant inputs. The proposed control scheme requires the execution of a small number of experiments to drive the system to the desired state in finite time, with nice convergence and robustness properties with respect to modeling inaccuracies as well as disturbances. To avoid the necessity of exactly reinitializing the system at each iteration, the basic method is modified so as to obtain a cyclic controller, by which the system is cyclically steered through an arbitrary sequence of states. As a case study, a carlike mobile robot is considered. Both simulation and experimental results are reported to show the performance of the method.

  16. Microsoft Word - ex15-ITER-sept10.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5 - Rights in Data-Special Works - ITER UT-B Contracts Div Sept 2010 Page 1 of 1 ex15-ITER-sept10.doc Exhibit 15-ITER Ref: FAR 52.227-17 RIGHTS IN DATA SPECIAL WORKS ITER ...

  17. Gas species, their evolution and segregation through the ITER vacuum systems

    SciTech Connect (OSTI)

    Pearce, R.J.H.; Antipenkov, Alexander; Bersier, Jean-Louis; Boussier, Bastien; Baylor, Larry R; Gardner, Walter L; Meitner, Steven J

    2012-01-01

    This paper takes the ITER fueling requirements and current knowledge of gas balance and exhaust from operating tokamaks to predict all likely gas inputs into the ITER Vacuum systems. Areas where gas dynamics modeling is relevant to the ITER design are highlighted. The design and operation of the ITER vacuum system gives an element of segregation of different gas flows and species. This paper analyses the time dependent gas segregation in the vacuum system resulting from different temperature dependences of cryogenic sorption and condensation processes of different gas species. As a specific example, the optimal transfer of Ar-41 through the vacuum system is studied with respect to its decay and the resulting effects on the design of system components.

  18. U.S. Contributions to ITER

    SciTech Connect (OSTI)

    Ned R. Sauthoff

    2005-05-13

    The United States participates in the ITER project and program to enable the study of the science and technology of burning plasmas, a key programmatic element missing from the world fusion program. The 2003 U.S. decision to enter the ITER negotiations followed an extensive series of community and governmental reviews of the benefits, readiness, and approaches to the study of burning plasmas. This paper describes both the technical and the organizational preparations and plans for U.S. participation in the ITER construction activity: in-kind contributions, staff contributions, and cash contributions as well as supporting physics and technology research. Near-term technical activities focus on the completion of R&D and design and mitigation of risks in the areas of the central solenoid magnet, shield/blanket, diagnostics, ion cyclotron system, electron cyclotron system, pellet fueling system, vacuum system, tritium processing system, and conventional systems. Outside the project, the U .S. is engaged in preparations for the test blanket module program. Organizational activities focus on preparations of the project management arrangements to maximize the overall success of the ITER Project; elements include refinement of U.S. directions on the international arrangements, the establishment of the U.S. Domestic Agency, progress along the path of the U.S. Department of Energy's Project Management Order, and overall preparations for commencement of the fabrication of major items of equipment and for provision of staff and cash as specified in the upcoming ITER agreement.

  19. Preliminary Master Logic Diagram for ITER operation

    SciTech Connect (OSTI)

    Cadwallader, L.C.; Taylor, N.P.; Poucet, A.E.

    1998-04-01

    This paper describes the work performed to develop a Master Logic Diagram (MLD) for the operations phase of the International Thermonuclear Experimental Reactor (ITER). The MLD is a probabilistic risk assessment tool used to identify the broad set of potential initiating events that could lead to an offsite radioactive or toxic chemical release from the facility under study. The MLD described here is complementary to the failure modes and effects analyses (FMEAs) that have been performed for ITER`s major plant systems in the engineering evaluation of the facility design. While the FMEAs are a bottom-up or component level approach, the MLD is a top-down or facility level approach to identifying the broad spectrum of potential events. Strengths of the MLD are that it analyzes the entire plant, depicts completeness in the accident initiator process, provides an independent method for identification, and can also identify potential system interactions. MLDs have been used successfully as a hazard analysis tool. This paper describes the process used for the ITER MLD to treat the variety of radiological and toxicological source terms present in the ITER design. One subtree of the nineteen page MLD is shown to illustrate the levels of the diagram.

  20. Global ICRF system designs for ITER and TPX

    SciTech Connect (OSTI)

    Goulding, R.H.; Hoffman, D.J.; Ryan, P.M.; Durodie, F.

    1995-09-01

    The design of feed networks for ICRF antenna arrays on ITER and TPX are discussed. Features which are present in one or both of the designs include distribution of power to several straps from a single generator, the capability to vary phases of the currents on antenna elements rapidly without the need to rematch, and passive elements which present a nearly constant load to the generators during ELM induced loading transients of a factor of I0 or more. The FDAC (Feedline/Decoupler/Antenna Calculator) network modeling code is described, which allows convenient modeling of the electrical performance of nearly arbitrary ICRF feed networks.

  1. DOE/SC Lehman Review of US ITER Project, USIPO,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    SC Lehman Review of US ITER Project, USIPO, Oak Ridge, Tennessee, April 5-7, 2011 - Ned Sauthoff Project Manager, US ITER INSIDE: ITER Site Progress Secret City View from DOE US Project Highlights Engaging Industry New PPPL Head of ITER Department PPPL to Cadarache New Division Director Positions Open at US ITER Upcoming Events ORNL 2011-G00858/jpp It has been a busy season for US ITER, as the team positions for fabrication in late-FY 12 and FY 13. Our priorities remain completing designs,

  2. Non-iterative Voltage Stability

    SciTech Connect (OSTI)

    Makarov, Yuri V.; Vyakaranam, Bharat; Hou, Zhangshuan; Wu, Di; Meng, Da; Wang, Shaobu; Elbert, Stephen T.; Miller, Laurie E.; Huang, Zhenyu

    2014-09-30

    This report demonstrates promising capabilities and performance characteristics of the proposed method using several power systems models. The new method will help to develop a new generation of highly efficient tools suitable for real-time parallel implementation. The ultimate benefit obtained will be early detection of system instability and prevention of system blackouts in real time.

  3. Iterative methods for distributed parameter estimation in parabolic PDE

    SciTech Connect (OSTI)

    Vogel, C.R.; Wade, J.G.

    1994-12-31

    The goal of the work presented is the development of effective iterative techniques for large-scale inverse or parameter estimation problems. In this extended abstract, a detailed description of the mathematical framework in which the authors view these problem is presented, followed by an outline of the ideas and algorithms developed. Distributed parameter estimation problems often arise in mathematical modeling with partial differential equations. They can be viewed as inverse problems; the `forward problem` is that of using the fully specified model to predict the behavior of the system. The inverse or parameter estimation problem is: given the form of the model and some observed data from the system being modeled, determine the unknown parameters of the model. These problems are of great practical and mathematical interest, and the development of efficient computational algorithms is an active area of study.

  4. COLLOQUIUM: Functional Capabilities and Design of the ITER EC...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MBG Auditorium, PPPL (284 cap.) COLLOQUIUM: Functional Capabilities and Design of the ITER EC H&CD System Dr. Mark Henderson ITER Organization A 24MW Electron Cyclotron (EC) system ...

  5. Annex I ITER Organization Service Contract General Conditions...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    All property of the Contractor while at the ITER Organization premises shall be at the risk of the Contractor and the ITER Organization shall accept no liability for any loss or...

  6. Annex I ITER Organization Service Contract General Conditions (2014)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I ITER Organization Service Contract General Conditions (2014) Page 1 of 21 GENERAL CONDITIONS FOR ITER ORGANIZATION SERVICE CONTRACTS (2014) Definitions ..................................................................................................................... 3 Article 1. Law and language of the Contract ................................................................................. 3 Article 2. Communications

  7. Axisymmetric Simulations of the ITER Vertical Stability Coil

    SciTech Connect (OSTI)

    Titus, Peter H.

    2013-07-09

    The ITER in-vessel coil system includes Vertical Stability (VS) coils and Edge Localized Mode (ELM) coils. There are two large VS ring coils, one upper and one lower. Each has four turns which are independently connected. The VS coils are needed for successful operation of ITER for most all of its operating modes. The VS coils must be highly reliable and fault tolerant. The operating environment includes normal and disruption Lorentz forces. To parametrically address all these design conditions in a tractable analysis requires a simplified model. The VS coils are predominately axisymmetric, and this suggests that an axisymmetric model can be meaningfully used to address the variations in mechanical design, loading, material properties, and time dependency. The axisymmetric finite element analysis described in this paper includes simulations of the bolted frictional connections used for the mounting details. Radiation and elastic-plastic response are modeled particularly for the extreme faulted conditions. Thermal connectivity is varied to study the effects of partial thermal connection of the actively cooled conductor to the remaining structure.

  8. Models and Datasets

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    iteration by iteration. RevSim is an Excel 2010 based model. Much of the logic is VBA code (Visual Basic for Applications); the user does not need to know VBA to run the...

  9. RIGHT OF ACCESS BY OTHERS - ITER (December 2013

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    RIGHT OF ACCESS BY OTHERS - ITER (December 2013) In order to ensure the quality and fitness of components and systems procured for ITER, the Company, ITER International Organization (IO), other ITER Domestic Agencies (DA), or authorized representatives of any of these organizations (e.g. inspectors) shall have right of access to Seller's (and any of its subcontractor's) premises to: - Witness acceptance tests; - Attend periodic meetings to monitor contract execution; - Perform reviews,

  10. A domain decomposition method of stochastic PDEs: An iterative solution techniques using a two-level scalable preconditioner

    SciTech Connect (OSTI)

    Subber, Waad Sarkar, Abhijit

    2014-01-15

    Recent advances in high performance computing systems and sensing technologies motivate computational simulations with extremely high resolution models with capabilities to quantify uncertainties for credible numerical predictions. A two-level domain decomposition method is reported in this investigation to devise a linear solver for the large-scale system in the Galerkin spectral stochastic finite element method (SSFEM). In particular, a two-level scalable preconditioner is introduced in order to iteratively solve the large-scale linear system in the intrusive SSFEM using an iterative substructuring based domain decomposition solver. The implementation of the algorithm involves solving a local problem on each subdomain that constructs the local part of the preconditioner and a coarse problem that propagates information globally among the subdomains. The numerical and parallel scalabilities of the two-level preconditioner are contrasted with the previously developed one-level preconditioner for two-dimensional flow through porous media and elasticity problems with spatially varying non-Gaussian material properties. A distributed implementation of the parallel algorithm is carried out using MPI and PETSc parallel libraries. The scalabilities of the algorithm are investigated in a Linux cluster.

  11. International Workshop: MFE Roadmapping in the ITER Era | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab International Workshop: MFE Roadmapping in the ITER Era International Workshop: MFE Roadmapping in the ITER Era Contact Information Website: International Workshop: MFE Roadmapping in the ITER Era Coordinator(s): Pamela Hampton phampton@pppl.gov Host(s): G.H. Neilson hneilson@pppl.gov Learn More Fusion roadmapping

  12. Main challenges for ITER optical diagnostics

    SciTech Connect (OSTI)

    Vukolov, K. Yu.; Orlovskiy, I. I.; Alekseev, A. G.; Borisov, A. A.; Andreenko, E. N.; Kukushkin, A. B.; Lisitsa, V. S.; Neverov, V. S.

    2014-08-21

    The review is made of the problems of ITER optical diagnostics. Most of these problems will be related to the intensive neutron radiation from hot plasma. At a high level of radiation loads the most types of materials gradually change their properties. This effect is most critical for optical diagnostics because of degradation of optical glasses and mirrors. The degradation of mirrors, that collect the light from plasma, basically will be induced by impurity deposition and (or) sputtering by charge exchange atoms. Main attention is paid to the search of glasses for vacuum windows and achromatic lens which are stable under ITER irradiation conditions. The last results of irradiation tests in nuclear reactor of candidate silica glasses KU-1, KS-4V and TF 200 are presented. An additional problem is discussed that deals with the stray light produced by multiple reflections from the first wall of the intense light emitted in the divertor plasma.

  13. The workshop on iterative methods for large scale nonlinear problems

    SciTech Connect (OSTI)

    Walker, H.F.; Pernice, M.

    1995-12-01

    The aim of the workshop was to bring together researchers working on large scale applications with numerical specialists of various kinds. Applications that were addressed included reactive flows (combustion and other chemically reacting flows, tokamak modeling), porous media flows, cardiac modeling, chemical vapor deposition, image restoration, macromolecular modeling, and population dynamics. Numerical areas included Newton iterative (truncated Newton) methods, Krylov subspace methods, domain decomposition and other preconditioning methods, large scale optimization and optimal control, and parallel implementations and software. This report offers a brief summary of workshop activities and information about the participants. Interested readers are encouraged to look into an online proceedings available at http://www.usi.utah.edu/logan.proceedings. In this, the material offered here is augmented with hypertext abstracts that include links to locations such as speakers` home pages, PostScript copies of talks and papers, cross-references to related talks, and other information about topics addresses at the workshop.

  14. Statistical properties of an iterated arithmetic mapping

    SciTech Connect (OSTI)

    Feix, M.R.; Rouet, J.L.

    1994-07-01

    We study the (3x = 1)/2 problem from a probabilistic viewpoint and show a forgetting mechanism for the last k binary digits of the seed after k iterations. The problem is subsequently generalized to a trifurcation process, the (lx + m)/3 problem. Finally the sequence of a set of seeds is empirically shown to be equivalent to a random walk of the variable log{sub 2}x (or log{sub 3} x) though computer simulations.

  15. US ITER is a strong contributor in plan to enhance international...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    US ITER is a strong contributor in plan to enhance international sharing of prime ITER real estate American Fusion News Category: U.S. ITER Link: US ITER is a strong contributor in ...

  16. A Comparison of Modifications to MELCOR versions 1.8.2 and 1.8.6 for ITER Safety Analysis

    SciTech Connect (OSTI)

    B. J. Merrill; P. W. Humrickhouse

    2010-06-01

    During the Engineering Design Activity of the International Thermonuclear Experimental Reactor (ITER), the MELCOR 1.8.2 code was selected as one of several codes to be used to perform ITER safety analyses [1]. MELCOR was chosen because it has the capability of predicting coolant pressure, temperature, mass flow rate, and radionuclide and aerosol transport in nuclear facilities and reactor cooling systems. MELCOR can also predict structural temperatures (e.g. first wall, blanket, divertor, and vacuum vessel) resulting from energy produced by radioactive decay heat and/or chemical reactions (oxidation). The Idaho National Laboratory (INL) Fusion Safety Program (FSP) made fusion specific modifications to the MELCOR 1.8.2 code [2-6], including models for water freezing, air condensation, beryllium, carbon, and tungsten oxidation in steam and air environments, flow boiling in coolant loops, and radiation in enclosures, that allowed MELCOR to assess the thermal hydraulic response of ITER cooling systems and the transport of radionuclides as aerosols during accident conditions. Recently, the ITER International Organization (IO) used a “pedigreed” version of MELCOR 1.8.2 [7] to perform accident analyses for ITER’s “Rapport Préliminaire de Sûreté” (Report Preliminary on Safety - RPrS). The MELCOR thermal-hydraulics code [8] is currently under development at the Sandia National Laboratory (SNL) for the US Nuclear Regulatory Commission (NRC). MELCOR is used to model the progression of severe accidents in light water fission reactors. Because MELCOR has undergone many improvements between version 1.8.2 and 1.8.6, the INL FSP decided to introduce fusion modifications into MELCOR 1.8.6, and thereby produce a version of MELCOR 1.8.6 with similar capabilities to the pedigreed version of MELCOR 1.8.2 used for the ITER RPrS. We have applied this version of MELCOR 1.8.6 to the same set of problems used in the MELCOR 1.8.2 pedigree analysis [7]. Section 2 describes a non

  17. Conformal mapping and convergence of Krylov iterations

    SciTech Connect (OSTI)

    Driscoll, T.A.; Trefethen, L.N.

    1994-12-31

    Connections between conformal mapping and matrix iterations have been known for many years. The idea underlying these connections is as follows. Suppose the spectrum of a matrix or operator A is contained in a Jordan region E in the complex plane with 0 not an element of E. Let {phi}(z) denote a conformal map of the exterior of E onto the exterior of the unit disk, with {phi}{infinity} = {infinity}. Then 1/{vert_bar}{phi}(0){vert_bar} is an upper bound for the optimal asymptotic convergence factor of any Krylov subspace iteration. This idea can be made precise in various ways, depending on the matrix iterations, on whether A is finite or infinite dimensional, and on what bounds are assumed on the non-normality of A. This paper explores these connections for a variety of matrix examples, making use of a new MATLAB Schwarz-Christoffel Mapping Toolbox developed by the first author. Unlike the earlier Fortran Schwarz-Christoffel package SCPACK, the new toolbox computes exterior as well as interior Schwarz-Christoffel maps, making it easy to experiment with spectra that are not necessarily symmetric about an axis.

  18. In-vessel ITER tubing failure rates for selected materials and coolants

    SciTech Connect (OSTI)

    Marshall, T.D.; Cadwallader, L.C.

    1994-03-01

    Several materials have been suggested for fabrication of ITER in-vessel coolant tubing: beryllium, copper, Inconel, niobium, stainless steel, titanium, and vanadium. This report generates failure rates for the materials to identify the best performer from an operational safety and availability perspective. Coolant types considered in this report are helium gas, liquid lithium, liquid sodium, and water. Failure rates for the materials are generated by including the influence of ITER`s operating environment and anticipated tubing failure mechanisms with industrial operating experience failure rates. The analyses define tubing failure mechanisms for ITER as: intergranular attack, flow erosion, helium induced swelling, hydrogen damage, neutron irradiation embrittlement, cyclic fatigue, and thermal cycling. K-factors, multipliers, are developed to model each failure mechanism and are applied to industrial operating experience failure rates to generate tubing failure rates for ITER. The generated failure rates identify the best performer by its expected reliability. With an average leakage failure rate of 3.1e-10(m-hr){sup {minus}1}and an average rupture failure rate of 3.1e-11(m-hr){sup {minus}1}, titanium proved to be the best performer of the tubing materials. The failure rates generated in this report are intended to serve as comparison references for design safety and optimization studies. Actual material testing and analyses are required to validate the failure rates.

  19. Tungsten dust impact on ITER-like plasma edge

    SciTech Connect (OSTI)

    Smirnov, R. D. Krasheninnikov, S. I.; Pigarov, A. Yu.; Rognlien, T. D.

    2015-01-15

    The impact of tungsten dust originating from divertor plates on the performance of edge plasma in ITER-like discharge is evaluated using computer modeling with the coupled dust-plasma transport code DUSTT-UEDGE. Different dust injection parameters, including dust size and mass injection rates, are surveyed. It is found that tungsten dust injection with rates as low as a few mg/s can lead to dangerously high tungsten impurity concentrations in the plasma core. Dust injections with rates of a few tens of mg/s are shown to have a significant effect on edge plasma parameters and dynamics in ITER scale tokamaks. The large impact of certain phenomena, such as dust shielding by an ablation cloud and the thermal force on tungsten ions, on dust/impurity transport in edge plasma and consequently on core tungsten contamination level is demonstrated. It is also found that high-Z impurities provided by dust can induce macroscopic self-sustained plasma oscillations in plasma edge leading to large temporal variations of edge plasma parameters and heat load to divertor target plates.

  20. Using AORSA to simulate helicon waves in DIIID and ITER

    SciTech Connect (OSTI)

    Lau, Cornwall H; Jaeger, E. F.; Berry, Lee Alan; Bertelli, Nicola; Green, David L; Murakami, Masanori; Park, J. M.; Prater, Ron

    2014-01-01

    Recent efforts by Vdovin [1] and Prater [2] have shown that helicon waves (fast waves at ~30 ion cyclotron frequency harmonic) may be an attractive option for driving efficient off-axis current drive during non-inductive tokamak operation for DIIID, ITER and DEMO. For DIIID scenarios, the ray tracing code GENRAY has been extensively used to study helicon current drive efficiency and location as a function many plasma parameters. has some limitations on absorption at high cyclotron harmonics, so the full wave code AORSA, which is applicable to arbitrary Larmor radius and can therefore resolve high ion cyclotron harmonics, has been recently used to validate the GENRAY model. It will be shown that the GENRAY and AORSA driven current drive profiles are comparable for the envisioned high temperature and density advanced scenarios for DIIID, where there is high single pass absorption due to electron Landau damping. AORSA results will be shown for various plasma parameters for DIIID and for ITER. Computational difficulties in achieving these AORSA results will also be discussed. * Work supported by USDOE Contract No. DE-AC05-00OR22725 [1] V. L. Vdovin, Plasma Physics Reports, V.39, No.2, 2013 [2] R. Prater et al, Nucl. Fusion, 52, 083024, 2014

  1. Tungsten dust impact on ITER-like plasma edge

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smirnov, R. D.; Krasheninnikov, S. I.; Pigarov, A. Yu.; Rognlien, T. D.

    2015-01-12

    The impact of tungsten dust originating from divertor plates on the performance of edge plasma in ITER-like discharge is evaluated using computer modeling with the coupled dust-plasma transport code DUSTT-UEDGE. Different dust injection parameters, including dust size and mass injection rates, are surveyed. It is found that tungsten dust injection with rates as low as a few mg/s can lead to dangerously high tungsten impurity concentrations in the plasma core. Dust injections with rates of a few tens of mg/s are shown to have a significant effect on edge plasma parameters and dynamics in ITER scale tokamaks. The large impactmore » of certain phenomena, such as dust shielding by an ablation cloud and the thermal force on tungsten ions, on dust/impurity transport in edge plasma and consequently on core tungsten contamination level is demonstrated. Lastly, it is also found that high-Z impurities provided by dust can induce macroscopic self-sustained plasma oscillations in plasma edge leading to large temporal variations of edge plasma parameters and heat load to divertor target plates.« less

  2. Tungsten dust impact on ITER-like plasma edge

    SciTech Connect (OSTI)

    Smirnov, R. D.; Krasheninnikov, S. I.; Pigarov, A. Yu.; Rognlien, T. D.

    2015-01-12

    The impact of tungsten dust originating from divertor plates on the performance of edge plasma in ITER-like discharge is evaluated using computer modeling with the coupled dust-plasma transport code DUSTT-UEDGE. Different dust injection parameters, including dust size and mass injection rates, are surveyed. It is found that tungsten dust injection with rates as low as a few mg/s can lead to dangerously high tungsten impurity concentrations in the plasma core. Dust injections with rates of a few tens of mg/s are shown to have a significant effect on edge plasma parameters and dynamics in ITER scale tokamaks. The large impact of certain phenomena, such as dust shielding by an ablation cloud and the thermal force on tungsten ions, on dust/impurity transport in edge plasma and consequently on core tungsten contamination level is demonstrated. Lastly, it is also found that high-Z impurities provided by dust can induce macroscopic self-sustained plasma oscillations in plasma edge leading to large temporal variations of edge plasma parameters and heat load to divertor target plates.

  3. Optical dumps for H-alpha and visible spectroscopy in ITER

    SciTech Connect (OSTI)

    Andreenko, E. N.; Alekseev, A. G.; Gorshkov, A. V.; Orlovskiy, I. I.

    2014-08-21

    High-reflective Beryllium cover of ITER first wall (R≈30–60%) causes remarkable increase of divertor stray light component (DSL). Optical dumps are well-known solution for DSL attenuation. In this work few types of optical dumps have been examined both by modeling and experimental studies. Taking into account the limitations, induced by ITER first wall design, OD optimized design has been proposed which could decrease divertor stray light component by 10..100 times depending on incidence angle of light.

  4. Occupational Radiation Exposure Analysis of US ITER DCLL TBM

    SciTech Connect (OSTI)

    Merrill, Brad J; Cadwallader, Lee C; Dagher, Mohamad

    2007-08-01

    This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

  5. A fresh look at electron cyclotron current drive power requirements for stabilization of tearing modes in ITER

    SciTech Connect (OSTI)

    La Haye, R. J.

    2015-12-10

    ITER is an international project to design and build an experimental fusion reactor based on the “tokamak” concept. ITER relies upon localized electron cyclotron current drive (ECCD) at the rational safety factor q=2 to suppress or stabilize the expected poloidal mode m=2, toroidal mode n=1 neoclassical tearing mode (NTM) islands. Such islands if unmitigated degrade energy confinement, lock to the resistive wall (stop rotating), cause loss of “H-mode” and induce disruption. The International Tokamak Physics Activity (ITPA) on MHD, Disruptions and Magnetic Control joint experiment group MDC-8 on Current Drive Prevention/Stabilization of Neoclassical Tearing Modes started in 2005, after which assessments were made for the requirements for ECCD needed in ITER, particularly that of rf power and alignment on q=2 [1]. Narrow well-aligned rf current parallel to and of order of one percent of the total plasma current is needed to replace the “missing” current in the island O-points and heal or preempt (avoid destabilization by applying ECCD on q=2 in absence of the mode) the island [2-4]. This paper updates the advances in ECCD stabilization on NTMs learned in DIII-D experiments and modeling during the last 5 to 10 years as applies to stabilization by localized ECCD of tearing modes in ITER. This includes the ECCD (inside the q=1 radius) stabilization of the NTM “seeding” instability known as sawteeth (m/n=1/1) [5]. Recent measurements in DIII-D show that the ITER-similar current profile is classically unstable, curvature stabilization must not be neglected, and the small island width stabilization effect from helical ion polarization currents is stronger than was previously thought [6]. The consequences of updated assumptions in ITER modeling of the minimum well-aligned ECCD power needed are all-in-all favorable (and well-within the ITER 24 gyrotron capability) when all effects are included. However, a “wild card” may be broadening of the localized

  6. Diverse Power Iteration Embeddings and Its Applications

    SciTech Connect (OSTI)

    Huang H.; Yoo S.; Yu, D.; Qin, H.

    2014-12-14

    Abstract—Spectral Embedding is one of the most effective dimension reduction algorithms in data mining. However, its computation complexity has to be mitigated in order to apply it for real-world large scale data analysis. Many researches have been focusing on developing approximate spectral embeddings which are more efficient, but meanwhile far less effective. This paper proposes Diverse Power Iteration Embeddings (DPIE), which not only retains the similar efficiency of power iteration methods but also produces a series of diverse and more effective embedding vectors. We test this novel method by applying it to various data mining applications (e.g. clustering, anomaly detection and feature selection) and evaluating their performance improvements. The experimental results show our proposed DPIE is more effective than popular spectral approximation methods, and obtains the similar quality of classic spectral embedding derived from eigen-decompositions. Moreover it is extremely fast on big data applications. For example in terms of clustering result, DPIE achieves as good as 95% of classic spectral clustering on the complex datasets but 4000+ times faster in limited memory environment.

  7. PPPL's Hawryluk Named ITER Deputy Director-General | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab PPPL's Hawryluk Named ITER Deputy Director-General By Patti Wieser March 8, 2011 Tweet Widget Google Plus One Share on Facebook Richard Hawryluk (Photo by Elle Starkman, PPPL Office of Communications) Richard Hawryluk Richard Hawryluk, a senior scientist at the DOE Princeton Plasma Physics Laboratory (PPPL), has been appointed deputy director-general of the ITER Organization and director of its administration department. The ITER project, currently under construction in France,

  8. Preliminary Neutronics Analysis of the ITER Toroidal Interferometer and

    Office of Scientific and Technical Information (OSTI)

    Polarimeter Diagnostic Corner Cube Retroreflectors (Journal Article) | SciTech Connect Preliminary Neutronics Analysis of the ITER Toroidal Interferometer and Polarimeter Diagnostic Corner Cube Retroreflectors Citation Details In-Document Search Title: Preliminary Neutronics Analysis of the ITER Toroidal Interferometer and Polarimeter Diagnostic Corner Cube Retroreflectors ITER is an international project under construction in France that will demonstrate nuclear fusion at a power

  9. Simulation and Analysis of the Hybrid Operating Mode in ITER

    SciTech Connect (OSTI)

    Kessel, C.E.; Budny, R.V.; Indireshkumar, K.

    2005-09-22

    The hybrid operating mode in ITER is examined with 0D systems analysis, 1.5D discharge scenario simulations using TSC and TRANSP, and the ideal MHD stability is discussed. The hybrid mode has the potential to provide very long pulses and significant neutron fluence if the physics regime can be produced in ITER. This paper reports progress in establishing the physics basis and engineering limitation for the hybrid mode in ITER.

  10. COLLOQUIUM: Handling Plasma Wall Interactions on ITER | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab June 8, 2015, 4:15pm to 6:30pm Colloquia MBG Auditorium COLLOQUIUM: Handling Plasma Wall Interactions on ITER Dr. Richard Pitts ITER Although the ITER machine design is essentially complete, with almost all major systems into the procurement phase, there are many physics issues which remain open and require continued investigation during the machine construction years in preparation for both early operation and the high performance burning plasma phases. Boundary physics and the

  11. THERMAL DESIGN OF THE ITER VACUUM VESSEL COOLING SYSTEM

    SciTech Connect (OSTI)

    Carbajo, Juan J; Yoder Jr, Graydon L; Kim, Seokho H

    2010-01-01

    RELAP5-3D models of the ITER Vacuum Vessel (VV) Primary Heat Transfer System (PHTS) have been developed. The design of the cooling system is described in detail, and RELAP5 results are presented. Two parallel pump/heat exchanger trains comprise the design one train is for full-power operation and the other is for emergency operation or operation at decay heat levels. All the components are located inside the Tokamak building (a significant change from the original configurations). The results presented include operation at full power, decay heat operation, and baking operation. The RELAP5-3D results confirm that the design can operate satisfactorily during both normal pulsed power operation and decay heat operation. All the temperatures in the coolant and in the different system components are maintained within acceptable operating limits.

  12. Microsoft Word - ex15-ITER-sept10.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    5 - Rights in Data-Special Works - ITER UT-B Contracts Div Sept 2010 Page 1 of 1 ex15-ITER-sept10.doc Exhibit 15-ITER Ref: FAR 52.227-17 RIGHTS IN DATA í SPECIAL WORKS í ITER (Sept 2010) (a) Definitions. (1) "Data", as used in this clause, means recorded information, regardless of form or the media on which it may be recorded. The term includes technical data and computer software. The term does not include information incidental to contract administration, such as financial,

  13. Microsoft Word - ex1b-ITER-mar07.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    B - Patent Rights - Acquisition by the Government - ITER UT-B Contracts Div March 2007 Page 1 of 6 ex1b-ITER-mar07.doc Exhibit 1B ITER Ref: DEAR 952.227-13 PATENT RIGHTS - ACQUISITION BY THE GOVERNMENT - ITER (Mar 2007) (a) Definitions. (1) "Invention", as used in this clause, means any invention or discovery which is or may be patentable or otherwise protectable under title 35 of the United States Code or any novel variety of plant that is or may be protectable under the Plant Variety

  14. Microsoft Word - ex9-ITER-june11.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    - Technical Data - ITER UT-B Contracts Div June 2011 Page 1 of 5 ex9-ITER-june11.doc Exhibit 9 ITER Ref: DEAR 927.409; FAR 52.227-14, 52.227-14 Alt.V, 52.227-16 TECHNICAL DATA - ITER (June 2011) 1. RIGHTS IN DATA - GENERAL (a) Definitions. (1) "Computer data bases," as used in this clause, means a collection of data in a form capable of, and for the purpose of, being stored in, processed, and operated on by a computer. The term does not include computer software. (2) "Computer

  15. Microsoft Word - ex9ed-ITER-june11.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ED - Technical Data - ITER UT-B Contracts Div June 2011 Page 1 of 5 ex9ed-ITER-june11.doc Exhibit 9ED ITER Ref: DEAR 927.409; FAR 52.227-14, 52.227-14 Alt. IV, 52.227-14 Alt. V, 52.227-16 TECHNICAL DATA - ITER (June 2011) 1. RIGHTS IN DATA-GENERAL (a) Definitions. (1) "Computer data bases," as used in this clause, means a collection of data in a form capable of, and for the purpose of, being stored in, processed, and operated on by a computer. The term does not include computer

  16. Microsoft Word - ex9rdf-ITER-sept09.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    RDF - Technical Data - ITER UT-B Contracts Div Sept 2009 Page 1 of 5 ex9rdf-ITER-sept09.doc Exhibit 9RDF-ITER Ref: DEAR 970.5227-1 TECHNICAL DATA - ITER (Sept 2009) 1. Rights in Data-Facilities. (a) Definitions. (1) "Computer Data Bases", as used in this clause, means a collection of data in a form capable of, and for the purpose of, being stored in, processed, and operated on by a computer. The term does not include Computer Software. (2) "Computer Software", as used in this

  17. Annex I ITER Organization Service Contract General Conditions...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Annex I ITER Organization Service Contract General Conditions (2014) Page 1 of 21 GENERAL ... 3 Article 1. Law and language of the Contract ......

  18. Technological Institute of Renewable Energy ITER | Open Energy...

    Open Energy Info (EERE)

    to: navigation, search Name: Technological Institute of Renewable Energy (ITER) Place: Santa Cruz de Tenerife, Spain Zip: 38611 Sector: Solar, Wind energy Product: Spain-based,...

  19. Physics and technology in the ion-cyclotron range of frequency on Tore Supra and TITAN test facility: implication for ITER

    SciTech Connect (OSTI)

    Litaudon, X; Bernard, J. M.; Colas, L.; Dumont, R. J.; Argouarch, A.; Bottollier-Curtet, H.; Bremond, S.; Champeaux, S.; Corre, Y.; Dumortier, P.; Firdaouss, M.; Guilhem, D.; Gunn, J. P.; Gouard, Ph.; Hoang, G T; Jacquot, Jonathan; Klepper, C Christopher; Kubic, M.; Kyrytsya, V.; Lombard, G.; Milanesio, D.; Messiaen, A.; Mollard, P.; Meyer, O.; Zarzoso, D.

    2013-01-01

    To support the design of an ITER ion-cyclotron range of frequency heating (ICRH) system and to mitigate risks of operation in ITER, CEA has initiated an ambitious Research & Development program accompanied by experiments on Tore Supra or test-bed facility together with a significant modelling effort. The paper summarizes the recent results in the following areas: Comprehensive characterization (experiments and modelling) of a new Faraday screen concept tested on the Tore Supra antenna. A new model is developed for calculating the ICRH sheath rectification at the antenna vicinity. The model is applied to calculate the local heat flux on Tore Supra and ITER ICRH antennas. Full-wave modelling of ITER ICRH heating and current drive scenarios with the EVE code. With 20 MW of power, a current of 400 kA could be driven on axis in the DT scenario. Comparison between DT and DT(3He) scenario is given for heating and current drive efficiencies. First operation of CW test-bed facility, TITAN, designed for ITER ICRH components testing and could host up to a quarter of an ITER antenna. R&D of high permittivity materials to improve load of test facilities to better simulate ITER plasma antenna loading conditions.

  20. Magnet design technical report---ITER definition phase

    SciTech Connect (OSTI)

    Henning, C.

    1989-04-28

    This report contains papers on the following topics: conceptual design; radiation damage of ITER magnet systems; insulation system of the magnets; critical current density and strain sensitivity; toroidal field coil structural analysis; stress analysis for the ITER central solenoid; and volt-second capabilities and PF magnet configurations.

  1. Registration of range data using a hybrid simulated annealing and iterative closest point algorithm

    SciTech Connect (OSTI)

    LUCK,JASON; LITTLE,CHARLES Q.; HOFF,WILLIAM

    2000-04-17

    The need to register data is abundant in applications such as: world modeling, part inspection and manufacturing, object recognition, pose estimation, robotic navigation, and reverse engineering. Registration occurs by aligning the regions that are common to multiple images. The largest difficulty in performing this registration is dealing with outliers and local minima while remaining efficient. A commonly used technique, iterative closest point, is efficient but is unable to deal with outliers or avoid local minima. Another commonly used optimization algorithm, simulated annealing, is effective at dealing with local minima but is very slow. Therefore, the algorithm developed in this paper is a hybrid algorithm that combines the speed of iterative closest point with the robustness of simulated annealing. Additionally, a robust error function is incorporated to deal with outliers. This algorithm is incorporated into a complete modeling system that inputs two sets of range data, registers the sets, and outputs a composite model.

  2. ITER Generic Diagnostic Upper Port Plug Nuclear Heating and Personnel Dose Rate Assesment Neutronics Analysis using the ATTILA Discrete Ordinates Code

    SciTech Connect (OSTI)

    Russell Feder and Mahmoud Z. Yousef

    2009-05-29

    Neutronics analysis to find nuclear heating rates and personnel dose rates were conducted in support of the integration of diagnostics in to the ITER Upper Port Plugs. Simplified shielding models of the Visible-Infrared diagnostic and of the ECH heating system were incorporated in to the ITER global CAD model. Results for these systems are representative of typical designs with maximum shielding and a small aperture (Vis-IR) and minimal shielding with a large aperture (ECH). The neutronics discrete-ordinates code ATTILA and SEVERIAN (the ATTILA parallel processing version) was used. Material properties and the 500 MW D-T volume source were taken from the ITER Brand Model MCNP benchmark model. A biased quadrature set equivelant to Sn=32 and a scattering degree of Pn=3 were used along with a 46-neutron and 21-gamma FENDL energy subgrouping. Total nuclear heating (neutron plug gamma heating) in the upper port plugs ranged between 380 and 350 kW for the Vis-IR and ECH cases. The ECH or Large Aperture model exhibited lower total heating but much higher peak volumetric heating on the upper port plug structure. Personnel dose rates are calculated in a three step process involving a neutron-only transport calculation, the generation of activation volume sources at pre-defined time steps and finally gamma transport analyses are run for selected time steps. ANSI-ANS 6.1.1 1977 Flux-to-Dose conversion factors were used. Dose rates were evaluated for 1 full year of 500 MW DT operation which is comprised of 3000 1800-second pulses. After one year the machine is shut down for maintenance and personnel are permitted to access the diagnostic interspace after 2-weeks if dose rates are below 100 ?Sv/hr. Dose rates in the Visible-IR diagnostic model after one day of shutdown were 130 ?Sv/hr but fell below the limit to 90 ?Sv/hr 2-weeks later. The Large Aperture or ECH style shielding model exhibited higher and more persistent dose rates. After 1-day the dose rate was 230 ?Sv

  3. A sequential partly iterative approach for multicomponent reactive transport with CORE2D

    SciTech Connect (OSTI)

    Samper, J.; Xu, T.; Yang, C.

    2008-11-01

    CORE{sup 2D} V4 is a finite element code for modeling partly or fully saturated water flow, heat transport and multicomponent reactive solute transport under both local chemical equilibrium and kinetic conditions. It can handle coupled microbial processes and geochemical reactions such as acid-base, aqueous complexation, redox, mineral dissolution/precipitation, gas dissolution/exsolution, ion exchange, sorption via linear and nonlinear isotherms, sorption via surface complexation. Hydraulic parameters may change due to mineral precipitation/dissolution reactions. Coupled transport and chemical equations are solved by using sequential iterative approaches. A sequential partly-iterative approach (SPIA) is presented which improves the accuracy of the traditional sequential noniterative approach (SNIA) and is more efficient than the general sequential iterative approach (SIA). While SNIA leads to a substantial saving of computing time, it introduces numerical errors which are especially large for cation exchange reactions. SPIA improves the efficiency of SIA because the iteration between transport and chemical equations is only performed in nodes with a large mass transfer between solid and liquid phases. The efficiency and accuracy of SPIA are compared to those of SIA and SNIA using synthetic examples and a case study of reactive transport through the Llobregat Delta aquitard in Spain. SPIA is found to be as accurate as SIA while requiring significantly less CPU time. In addition, SPIA is much more accurate than SNIA with only a minor increase in computing time. A further enhancement of the efficiency of SPIA is achieved by improving the efficiency of the Newton-Raphson method used for solving chemical equations. Such an improvement is obtained by working with increments of log-concentrations and ignoring the terms of the Jacobian matrix containing derivatives of activity coefficients. A proof is given for the symmetry and non-singularity of the Jacobian matrix

  4. US ITER is a strong contributor in plan to enhance international...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A port plug integration proposal developed with the US ITER diagnostics team has helped the international ITER collaboration arrive at a clever solution for safely housing all of ...

  5. Microsoft Word - Second_ ITER Council Press Release.doc

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Neil Calder Tel: 00 33 (0)6 14 16 41 75 ITER GAINS MOMENTUM Aomori, Japan 18 June 2008 On 17-18 June 2008, the ITER Council, the Governing Body of the new international Organization, convened for its second meeting. The two day meeting in Aomori, Japan, brought together senior representatives from the seven ITER Members: China, the European Union, India, Japan, Korea, Russia and the United States. Mr. Shingo Mimura, Governor of the Aomori Prefecture, welcomed delegates with a reminder of the

  6. Electrostatic Dust Detection and Removal for ITER

    SciTech Connect (OSTI)

    C.H. Skinner; A. Campos; H. Kugel; J. Leisure; A.L. Roquemore; S. Wagner

    2008-09-01

    We present some recent results on two innovative applications of microelectronics technology to dust inventory measurement and dust removal in ITER. A novel device to detect the settling of dust particles on a remote surface has been developed in the laboratory. A circuit board with a grid of two interlocking conductive traces with 25 μm spacing is biased to 30 – 50 V. Carbon particles landing on the energized grid create a transient short circuit. The current flowing through the short circuit creates a voltage pulse that is recorded by standard nuclear counting electronics and the total number of counts is related to the mass of dust impinging on the grid. The particles typically vaporize in a few seconds restoring the previous voltage standoff. Experience on NSTX however, showed that in a tokamak environment it was still possible for large particles or fibers to remain on the grid causing a long term short circuit. We report on the development of a gas puff system that uses helium to clear such particles. Experiments with varying nozzle designs, backing pressures, puff durations, and exit flow orientations have given an optimal configuration that effectively removes particles from an area up to 25 cm² with a single nozzle. In a separate experiment we are developing an advanced circuit grid of three interlocking traces that can generate a miniature electrostatic traveling wave for transporting dust to a suitable exit port. We have fabricated such a 3-pole circuit board with 25 micron insulated traces that operates with voltages up to 200 V. Recent results showed motion of dust particles with the application of only 50 V bias voltage. Such a device could potentially remove dust continuously without dedicated interventions and without loss of machine availability for plasma operations.

  7. An Overview Of The ITER In-Vessel Coil Systems

    SciTech Connect (OSTI)

    Heitzenroeder, P J; Chrzanowski, J H; Dahlgren, F; Hawryluk, R J; Loesser, G D; Neumeyer, C; Mansfield, C; Smith, J P; Schaffer, M; Humphreys, D; Cordier, J J; Campbell, D; Johnson, G A; Martin, A; Rebut, P H; Tao, J O; Fogarty, P J; Nelson, B E

    2009-09-24

    ELM mitigation is of particular importance in ITER in order to prevent rapid erosion or melting of the divertor surface, with the consequent risk of water leaks, increased plasma impurity content and disruptivity. Exploitable "natural" small or no ELM regimes might yet be found which extrapolate to ITER but this cannot be depended upon. Resonant Magnetic Perturbation has been added to pellet pacing as a tool for ITER to mitigate ELMs. Both are required, since neither method is fully developed and much work remains to be done. In addition, in-vessel coils enable vertical stabilization and RWM control. For these reasons, in-vessel coils (IVCs) are being designed for ITER to provide control of Edge Localized Modes (ELMs) in addition to providing control of moderately unstable resistive wall modes (RWMs) and the vertical stability (VS) of the plasma.

  8. Princeton Plasma Physics Lab - U.S. ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Video Looks at ITER http:www.pppl.govnode1536

  9. PPPL's Hawryluk Named ITER Deputy Director-General | Princeton...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... ITER, named for the Latin word for "the way," has seven project partners, including China, the European Union, India, Japan, Russia, South Korea, and the U.S. PPPL is part of the ...

  10. United States and International Partners Initial ITER Agreement |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy International Partners Initial ITER Agreement United States and International Partners Initial ITER Agreement May 24, 2006 - 10:48am Addthis Paves the Way for Large-Scale, Clean Fusion Energy Project BRUSSELS, BELGIUM - Representing the United States, Dr. Raymond L. Orbach, Director of the U.S. Department of Energy's (DOE) Office of Science, joined counterparts from China, the European Union, India, Japan, the Republic of Korea, and the Russian Federation today to

  11. PPPL's Rich Hawryluk recognized for service to ITER international fusion

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    project | Princeton Plasma Physics Lab PPPL's Rich Hawryluk recognized for service to ITER international fusion project By John Greenwald July 23, 2013 Tweet Widget Google Plus One Share on Facebook (Photo by U.S. Department of Energy) Gallery: From left, Energy Secretary Ernest Moniz and Rich Hawryluk (Photo by U.S. Department of Energy) From left, Energy Secretary Ernest Moniz and Rich Hawryluk Rich Hawryluk served as Deputy Director-General for the ITER Organization and Director of the

  12. A review of the US joining technologies for plasma facing components in the ITER fusion reactor

    SciTech Connect (OSTI)

    Odegard, B.C. Jr.; Cadden, C.H.; Watson, R.D.; Slattery, K.T.

    1998-02-01

    This paper is a review of the current joining technologies for plasma facing components in the US for the International Thermonuclear Experimental Reactor (ITER) project. Many facilities are involved in this project. Many unique and innovative joining techniques are being considered in the quest to join two candidate armor plate materials (beryllium and tungsten) to a copper base alloy heat sink (CuNiBe, OD copper, CuCrZr). These techniques include brazing and diffusion bonding, compliant layers at the bond interface, and the use of diffusion barrier coatings and diffusion enhancing coatings at the bond interfaces. The development and status of these joining techniques will be detailed in this report.

  13. Design of a diagnostic residual gas analyzer for the ITER divertor

    SciTech Connect (OSTI)

    Klepper, C Christopher; Biewer, T. M.; Graves, Van B; Andrew, P.; Marcus, Chris; Shimada, M.; Hughes, S.; Boussier, B.; Johnson, D. W.; Gardner, W. L.; Hillis, D. L.; Vayakis, G.; Vayakis, G.; Walsh, M.

    2015-01-01

    One of the ITER diagnostics having reached an advanced design stage is a diagnostic RGA for the divertor, i.e. residual gas analysis system for the ITER divertor, which is intended to sample the divertor pumping duct region during the plasma pulse and to have a response time compatible with plasma particle and impurity lifetimes in the divertor region. Main emphasis is placed on helium (He) concentration in the ducts, as well as the relative concentration between the hydrogen isotopes (H2, D2, T2). Measurement of the concentration of radiative gases, such as neon (Ne) and nitrogen (N2), is also intended. Numerical modeling of the gas flow from the sampled region to the cluster of analysis sensors, through a long (~8m long, ~110mm diameter) sampling pipe terminating in a pressure reducing orifice, confirm that the desired response time (~1s for He or D2) is achieved with the present design.

  14. Science and Technology Research and Development in Support to ITER and the Broader Approach at CEA

    SciTech Connect (OSTI)

    Becoulet, A.; Hoang, G T; Abiteboul, J.; Achard, J.; Alarcon, T.; Klepper, C Christopher

    2013-01-01

    In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented.

  15. Evaluation of graphite/steam interactions for ITER (International Thermonuclear Experimental Reactor)

    SciTech Connect (OSTI)

    Smolik, G.R.; Merrill, B.J.; Piet, S.J.; Holland, D.F.

    1990-09-01

    In this report we present the results of an experimental/analytical study designed to determine the quantity of hydrogen generated during a coolant inleakage accident in ITER. This hydrogen could represent a potential explosive hazard, provided the proper conditions exist, causing machine damage and release of radioactive material. We have measured graphite/steam reaction rates for several graphites and carbon-based composites at temperatures between 1000 C and 1700 C. The effects of steam flow rate, and partial pressure were also examined. The measured reaction rates correlated well with two Arrhenius type relationships. We have used the relationships for GraphNOL N3M in a thermal model to determine that for ITER the quantity of hydrogen produced would range between 5 and 35 kg, depending upon how the graphite tiles are attached to the first wall. While 5 kg is not a significant concern, 35 kg presents an explosive hazard. 20 refs., 14 figs., 1 tab.

  16. The ITER 3D Magnetic Diagnostic Response to Applied n=3 and n=4 RMP's

    SciTech Connect (OSTI)

    Lazerson, S A

    2014-09-01

    The ITER magnetic diagnostic response to applied n=3 and n=4 RMPs has been calculated for the 15MA scenario. The VMEC code was utilized to calculate free boundary 3D ideal MHD equilibria, where the non-stellarator symmetric terms were included in the calculation. This allows an assessment to be made of the possible boundary displacements due to RMP application in ITER. As the VMEC code assumes a continuous set of nested flux surface, the possibility of island and stochastic region formation is ignored. At the start of the current at-top (L-Mode) application of n = 4 RMP's indicates approximately 1 cm peak-to-peak displacements on the low field side of the plasma while later in the shot (H-mode) perturbations as large as 3 cm are present. Forward modeling of the ITER magnetic diagnostics indicates significant non-axisymmetric plasma response, exceeding 10% the axisymmetric signal in many of the flux loops. Magnetic field probes seem to indicate a greater robustness to 3D effects but still indicate large sensitivities to 3D effects in a number of sensors. Forward modeling of the diagnostics response to 3D equilibria allows assessment of diagnostics design and control scenarios.

  17. Benchmark of numerical tools simulating beam propagation and secondary particles in ITER NBI

    SciTech Connect (OSTI)

    Sartori, E. Veltri, P.; Serianni, G.; Dlougach, E.; Hemsworth, R.; Singh, M.

    2015-04-08

    Injection of high energy beams of neutral particles is a method for plasma heating in fusion devices. The ITER injector, and its prototype MITICA (Megavolt ITER Injector and Concept Advancement), are large extrapolations from existing devices: therefore numerical modeling is needed to set thermo-mechanical requirements for all beam-facing components. As the power and charge deposition originates from several sources (primary beam, co-accelerated electrons, and secondary production by beam-gas, beam-surface, and electron-surface interaction), the beam propagation along the beam line is simulated by comprehensive 3D models. This paper presents a comparative study between two codes: BTR has been used for several years in the design of the ITER HNB/DNB components; SAMANTHA code was independently developed and includes additional phenomena, such as secondary particles generated by collision of beam particles with the background gas. The code comparison is valuable in the perspective of the upcoming experimental operations, in order to prepare a reliable numerical support to the interpretation of experimental measurements in the beam test facilities. The power density map calculated on the Electrostatic Residual Ion Dump (ERID) is the chosen benchmark, as it depends on the electric and magnetic fields as well as on the evolution of the beam species via interaction with the gas. Finally the paper shows additional results provided by SAMANTHA, like the secondary electrons produced by volume processes accelerated by the ERID fringe-field towards the Cryopumps.

  18. A comparison of conjugate gradient, SIP, and other iterative methods for the solution of Poisson's equation with irregular boundary conditions

    SciTech Connect (OSTI)

    Bergmann, D.J.

    1990-06-01

    Several well known iterative methods for solving Poisson's equation, including Strongly Implicit Procedure and several preconditioned conjugate gradient methods are first applied to a problem with simple boundary conditions and a known solution. Then a problem with more complicated boundary conditions, similar to those encountered when modeling AVLIS plasmas, is solved. Differences in the solutions of the various methods are examined through the use of Fourier analysis. It was found that combinations of different iterative schemes will in some cases be the most efficient method of solution. 22 refs., 29 figs.

  19. Examination of the Entry to Burn and Burn Control for the ITER 15 MA Baseline and Other Scenarios

    SciTech Connect (OSTI)

    Kesse, Charles E.; Kim, S-H.; Koechl, F.

    2014-09-01

    The entry to burn and flattop burn control in ITER will be a critical need from the first DT experiments. Simulations are used to address time-dependent behavior under a range of possible conditions that include injected power level, impurity content (W, Ar, Be), density evolution, H-mode regimes, controlled parameter (Wth, Pnet, Pfusion), and actuator (Paux, fueling, fAr), with a range of transport models. A number of physics issues at the L-H transition require better understanding to project to ITER, however, simulations indicate viable control with sufficient auxiliary power (up to 73 MW), while lower powers become marginal (as low as 43 MW).

  20. DESIGN, ANALYSIS AND TEST CONCEPT FOR PROTOTYPE CRYOLINE OF ITER

    SciTech Connect (OSTI)

    Sarkar, B.; Badgujar, S.; Vaghela, H.; Shah, N.; Bhattacharya, R.; Chakrapani, Ch.

    2008-03-16

    The ITER cryo-distribution and cryoline is a part of the in-kind supply for India. The design of the systems is in progress. The topology of torus and neutral beam cryoline is defined as six process pipes along with thermal shield at 80 K and outer vacuum jacket. In order to develop confidence in the concept and to establish the high level of engineering and manufacturing technology, a prototype testing has been proposed. The prototype test will be carried out on 1:1 model in terms of dimension. However, the mass flow rate of the supercritical helium at 4.5 K and gaseous helium at 80 K will be on a 1:10 scale. The prototype cryoline has been designed and analyzed for thermal, structural and hydraulic parameters. The objective of this prototype test is to verify mechanical behavior due to thermal stress and pressure force, thermal and hydraulic performances. The concept of test facility has been realized along with the Piping and Instrumentation (P and I) diagram, instrumentation, controls, data acquisition, 80 K helium generation system along with supply and return valve boxes and interfacing hardware. The design concept, methodology for analysis and results, as well as the test facility have been discussed.

  1. EC assisted start-up experiments reproduction in FTU and AUG for simulations of the ITER case

    SciTech Connect (OSTI)

    Granucci, G.; Ricci, D.; Farina, D.; Figini, L.; Cavinato, M.; Stober, J.; Tudisco, O.

    2014-02-12

    The breakdown and plasma start-up in ITER are well known issues studied in the last few years in many tokamaks with the aid of calculation based on simplified modeling. The thickness of ITER metallic wall and the voltage limits of the Central Solenoid Power Supply strongly limit the maximum toroidal electric field achievable (0.3 V/m), well below the level used in the present generation of tokamaks. In order to have a safe and robust breakdown, the use of Electron Cyclotron Power to assist plasma formation and current rump up has been foreseen. This has raised attention on plasma formation phase in presence of EC wave, especially in order to predict the required power for a robust breakdown in ITER. Few detailed theory studies have been performed up to nowadays, due to the complexity of the problems. A simplified approach, extended from that proposed in ref[1] has been developed including a impurity multispecies distribution and an EC wave propagation and absorption based on GRAY code. This integrated model (BK0D) has been benchmarked on ohmic and EC assisted experiments on FTU and AUG, finding the key aspects for a good reproduction of data. On the basis of this, the simulation has been devoted to understand the best configuration for ITER case. The dependency of impurity distribution content and neutral gas pressure limits has been considered. As results of the analysis a reasonable amount of power (1 - 2 MW) seems to be enough to extend in a significant way the breakdown and current start up capability of ITER. The work reports the FTU data reproduction and the ITER case simulations.

  2. Commitment to Public Involvement

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Create a Sustainable Future Commitment to Public Involvement Commitment to Public Involvement LANL is committed to our neighbors August 1, 2013 Lab Director McMillan talks with...

  3. Electromagnetic analysis of forces and torques on the baseline and enhanced ITER shield modules due to plasma disruption.

    SciTech Connect (OSTI)

    Kotulski, Joseph Daniel; Coats, Rebecca Sue; Pasik, Michael Francis; Ulrickson, Michael Andrew

    2009-08-01

    An electromagnetic analysis is performed on the ITER shield modules under different plasma-disruption scenarios using the OPERA-3d software. The models considered include the baseline design as provided by the International Organization and an enhanced design that includes the more realistic geometrical features of a shield module. The modeling procedure is explained, electromagnetic torques are presented, and results of the modeling are discussed.

  4. US ITER is a strong contributor in plan to enhance international sharing of

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    prime ITER real estate | Princeton Plasma Physics Lab US ITER is a strong contributor in plan to enhance international sharing of prime ITER real estate By Lynne Degitz, US ITER March 28, 2013 Tweet Widget Google Plus One Share on Facebook PPPL's Russell Feder, left, and David Johnson developed key features for a modular approach to housing the extensive diagnostic systems that will be installed on the ITER tokamak. (Photo by Elle Starkman/PPPL Office of Communications) PPPL's Russell Feder,

  5. Modeling and Analysis of Alternative Concept of ITER Vacuum Vessel...

    Office of Scientific and Technical Information (OSTI)

    in Google Scholar Search WorldCat Search WorldCat to find libraries that may hold this journal Have feedback or suggestions for a way to improve these results? Save Share...

  6. ITER diagnostic systems in development in Ioffe Institute

    SciTech Connect (OSTI)

    Petrov, M.; Afanasyev, V.; Petrov, S.; Mironov, M.; Mukhin, E.; Tolstyakov, S.; Chugunov, I.; Shevelev, A.

    2014-08-21

    Three diagnostic systems are being developed in Ioffe Institute for ITER. Those are Neutral Particle Analysis (NPA), Thomson Scattering in Divertor (TSD) and Gamma Spectroscopy (GS). The main objective of NPA in ITER is to measure D/T fuel ration in plasma on the basis of measurement of neutralized fluxes of D and T ions [1]. Fuel ratio is one of the key parameters needed by ITER control system to provide the optimal conditions in plasma and the most effective plasma burning. Another objective is to measure the distribution function of fast ions (including alpha particles) generated as a result of the additional heating and nuclear fusion reactions. Thomson Scattering in Divertor (TSD) [2] will be used to measure electron temperature and density in the scrape-off layer in outer leg of ITER divertor. The main task of TSD is to protect the machine from divertor overloading. Gamma Spectroscopy (GS) [3] is based on the measurement of spectral lines of MeV range gammas generated in nuclear reactions in plasma. 2-D gamma-ray emission measurements give valuable information on the confined alpha particles in DT plasma. They also provide important information on the location of MeV range runaway electron beams in ITER plasma. For all three cases the physical basis and instrumentation are presented. The simple NPA version for measurements of D/T ratio in DEMO is also briefly described.

  7. Momentum space iterative solution of the time-dependent Schrödinger equation

    SciTech Connect (OSTI)

    Kiss, G. Zs.; Borbély, S.; Nagy, L.

    2013-11-13

    We present a novel approach, the iterative solution of the time-dependent Schrödinger equation (iTDSE model), for the investigation of atomic systems interacting with external laser fields. This model is the extension of the momentum-space strong-field approximation (MSSFA) [1], in which the Coulomb potential was considered only as a first order perturbation. In the iTDSE approach higher order terms were gradually introduced until convergence was achieved. Benchmark calculations were done on the hydrogen atom, and the obtained results were compared to the direct numerical solution [2].

  8. Diamond neutral particle spectrometer for fusion reactor ITER

    SciTech Connect (OSTI)

    Krasilnikov, V.; Amosov, V.; Kaschuck, Yu.; Skopintsev, D.

    2014-08-21

    A compact diamond neutral particle spectrometer with digital signal processing has been developed for fast charge-exchange atoms and neutrons measurements at ITER fusion reactor conditions. This spectrometer will play supplementary role for Neutral Particle Analyzer providing 10 ms time and 30 keV energy resolutions for fast particle spectra in non-tritium ITER phase. These data will also be implemented for independent studies of fast ions distribution function evolution in various plasma scenarios with the formation of a single fraction of high-energy ions. In tritium ITER phase the DNPS will measure 14 MeV neutrons spectra. The spectrometer with digital signal processing can operate at peak counting rates reaching a value of 10{sup 6} cps. Diamond neutral particle spectrometer is applicable to future fusion reactors due to its high radiation hardness, fast response and high energy resolution.

  9. Description of the prototype diagnostic residual gas analyzer for ITER

    SciTech Connect (OSTI)

    Younkin, T. R.; Biewer, T. M.; Klepper, C. C.; Marcus, C.

    2014-11-15

    The diagnostic residual gas analyzer (DRGA) system to be used during ITER tokamak operation is being designed at Oak Ridge National Laboratory to measure fuel ratios (deuterium and tritium), fusion ash (helium), and impurities in the plasma. The eventual purpose of this instrument is for machine protection, basic control, and physics on ITER. Prototyping is ongoing to optimize the hardware setup and measurement capabilities. The DRGA prototype is comprised of a vacuum system and measurement technologies that will overlap to meet ITER measurement requirements. Three technologies included in this diagnostic are a quadrupole mass spectrometer, an ion trap mass spectrometer, and an optical penning gauge that are designed to document relative and absolute gas concentrations.

  10. Status of research toward the ITER disruption mitigation system

    SciTech Connect (OSTI)

    Hollmann, E. M.; Izzo, V. A.; Aleynikov, P. B.; Lehnen, M.; Snipes, J. A.; Fülöp, T.; Humphreys, D. A.; Lukash, V. E.; Papp, G.; Pautasso, G.; Saint-Laurent, F.

    2015-02-15

    An overview of the present status of research toward the final design of the ITER disruption mitigation system (DMS) is given. The ITER DMS is based on massive injection of impurities, in order to radiate the plasma stored energy and mitigate the potentially damaging effects of disruptions. The design of this system will be extremely challenging due to many physics and engineering constraints such as limitations on port access and the amount and species of injected impurities. Additionally, many physics questions relevant to the design of the ITER disruption mitigation system remain unsolved such as the mechanisms for mixing and assimilation of injected impurities during the rapid shutdown and the mechanisms for the subsequent formation and dissipation of runaway electron current.

  11. Recent progress and advances in iterative software (including parallel aspects)

    SciTech Connect (OSTI)

    Carey, G.; Young, D.M.; Kincaid, D.

    1994-12-31

    The purpose of the workshop is to provide a forum for discussion of the current state of iterative software packages. Of particular interest is software for large scale engineering and scientific applications, especially for distributed parallel systems. However, the authors will also review the state of software development for conventional architectures. This workshop will complement the other proposed workshops on iterative BLAS kernels and applications. The format for the workshop is as follows: To provide some structure, there will be brief presentations, each of less than five minutes duration and dealing with specific facets of the subject. These will be designed to focus the discussion and to stimulate an exchange with the participants. Issues to be covered include: The evolution of iterative packages, current state of the art, the parallel computing challenge, applications viewpoint, standards, and future directions and open problems.

  12. Is Carbon a Realistic Choice for ITER's Divertor?

    SciTech Connect (OSTI)

    C.H. Skinner; G. Federici

    2005-05-13

    Tritium retention by co-deposition with carbon on the divertor target plate is predicted to limit ITER's DT burning plasma operations (e.g. to about 100 pulses for the worst conditions) before the in-vessel tritium inventory limit, currently set at 350 g, is reached. At this point, ITER will only be able to continue its burning plasma program if technology is available that is capable of rapidly removing large quantities of tritium from the vessel with over 90% efficiency. The removal rate required is four orders of magnitude faster than that demonstrated in current tokamaks. Eighteen years after the observation of co-deposition on JET and TFTR, such technology is nowhere in sight. The inexorable conclusion is that either a major initiative in tritium removal should be funded or that research priorities for ITER should focus on metal alternatives.

  13. Proposals for ITER Ion Cyclotron Reference Design Upgrades

    SciTech Connect (OSTI)

    Bosia, G.; Beaumont, B.; Bremond, S.; Vulliez, K.; Testoni, P.

    2005-09-26

    A possible issue for the ITER Ion Cyclotron Heating and Current Drive system is related to the high electric field (2 kV/mm parallel to B0) at which the array is planned to operate, which may be associated to a low dielectric rigidity of the of the vessel 'vacuum'. The combined effects are likely to set the upper limit to the RF power transfer efficiency to the plasma core. This paper addresses the problem of how to improve the power handling in the ITER IC launcher described in the ITER Final Design Report (FDR), to either operate at a significantly lower E-field in the torus vacuum or, alternatively, at a lower plasma coupling.

  14. Migration of vectorized iterative solvers to distributed memory architectures

    SciTech Connect (OSTI)

    Pommerell, C.; Ruehl, R.

    1994-12-31

    Both necessity and opportunity motivate the use of high-performance computers for iterative linear solvers. Necessity results from the size of the problems being solved-smaller problems are often better handled by direct methods. Opportunity arises from the formulation of the iterative methods in terms of simple linear algebra operations, even if this {open_quote}natural{close_quotes} parallelism is not easy to exploit in irregularly structured sparse matrices and with good preconditioners. As a result, high-performance implementations of iterative solvers have attracted a lot of interest in recent years. Most efforts are geared to vectorize or parallelize the dominating operation-structured or unstructured sparse matrix-vector multiplication, or to increase locality and parallelism by reformulating the algorithm-reducing global synchronization in inner products or local data exchange in preconditioners. Target architectures for iterative solvers currently include mostly vector supercomputers and architectures with one or few optimized (e.g., super-scalar and/or super-pipelined RISC) processors and hierarchical memory systems. More recently, parallel computers with physically distributed memory and a better price/performance ratio have been offered by vendors as a very interesting alternative to vector supercomputers. However, programming comfort on such distributed memory parallel processors (DMPPs) still lags behind. Here the authors are concerned with iterative solvers and their changing computing environment. In particular, they are considering migration from traditional vector supercomputers to DMPPs. Application requirements force one to use flexible and portable libraries. They want to extend the portability of iterative solvers rather than reimplementing everything for each new machine, or even for each new architecture.

  15. United States Research and Development effort on ITER magnet tasks

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Martovetsky, Nicolai N.; Reierson, Wayne T.

    2011-01-22

    This study presents the status of research and development (R&D) magnet tasks that are being performed in support of the U.S. ITER Project Office (USIPO) commitment to provide a central solenoid assembly and toroidal field conductor for the ITER machine to be constructed in Cadarache, France. The following development tasks are presented: winding development, inlets and outlets development, internal and bus joints development and testing, insulation development and qualification, vacuum-pressure impregnation, bus supports, and intermodule structure and materials characterization.

  16. Bragg x-ray survey spectrometer for ITER

    SciTech Connect (OSTI)

    Varshney, S. K.; Jakhar, S.; Barnsley, R.; O'Mullane, M. G.

    2012-10-15

    Several potential impurity ions in the ITER plasmas will lead to loss of confined energy through line and continuum emission. For real time monitoring of impurities, a seven channel Bragg x-ray spectrometer (XRCS survey) is considered. This paper presents design and analysis of the spectrometer, including x-ray tracing by the Shadow-XOP code, sensitivity calculations for reference H-mode plasma and neutronics assessment. The XRCS survey performance analysis shows that the ITER measurement requirements of impurity monitoring in 10 ms integration time at the minimum levels for low-Z to high-Z impurity ions can largely be met.

  17. Intel C++ compiler error: stl_iterator_base_types.h

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    C++ compiler error: stl_iterator_base_types.h Intel C++ compiler error: stl_iterator_base_types.h December 7, 2015 by Scott French Because the system-supplied version of GCC is relatively old (4.3.4) it is common practice to load the gcc module on our Cray systems when C++11 support is required under the Intel C++ compilers. While this works as expected under the GCC 4.8 and 4.9 series compilers, the 5.x series can cause Intel C++ compile-time errors similar to the following:

  18. PTRANSP Tests of TGLF and Predictions for ITER

    SciTech Connect (OSTI)

    Robert V. Budny, Xingqiu Yuan, S. Jardin, G. Hammett, G. Staebler, J. Kinsey, members of the ITPA Transport and Confinement Topical Group, and JET EFDA Contributors

    2012-09-23

    A new numerical solver for stiff transport predictions has been developed and implemented in the PTRANSP predictive transport code. The TGLF and GLF23 predictive codes have been incorporated in the solver, verified by comparisons with predictions from the XPTOR code, and validated by comparing predicted and measured profiles. Predictions for ITER baseline plasmas are presented.

  19. Overview of Recent Developments in Pellet Injection for ITER

    SciTech Connect (OSTI)

    Combs, Stephen Kirk; Baylor, Larry R; Meitner, Steven J; Caughman, John B; Rasmussen, David A; Maruyama, So

    2012-01-01

    Pellet injection is the primary fueling technique planned for core fueling of ITER burning plasmas. Also, the injection of relatively small pellets to purposely trigger rapid small edge localized modes (ELMs) has been proposed as a possible solution to the heat flux damage from larger natural ELMs likely to be an issue on the ITER divertor surfaces. The ITER pellet injection system is designed to inject pellets into the plasma through both inner and outer wall guide tubes. The inner wall guide tubes will provide high throughput pellet fueling while the outerwall guide tubes will be used primarily to trigger ELMs at a high frequency (>15 Hz). The pellet fueling rate ofeach injector is to be up to 120 Pa-m3/s, which will require the formation of solid D-T at a volumetric rate of ~1500 mm3/s. Two injectors are to be provided for ITER at the startup with a provision for up to six injectorsduring the D-T phase. The required throughput of each injector is greater than that of any injector built to date, and a novel twin-screw continuous extrusion system is being developed to meet the challenging design parameters. Status of the development activities will be presented, highlighting recent progress.

  20. Visions for Data Management and Remote Collaboration on ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    I P 0.9 MA P IN 2.3 MW H98 1.3 M. Greenwald, et al., APS-DPP November 2007 C-Mod Data Helps Break Covariance Between EFF and nn G Makes Extrapolation To ITER More...

  1. TGLF Recalibration for ITER Standard Case Parameters FY2015: Theory and Simulation Performance Target Final Report

    SciTech Connect (OSTI)

    Candy, J.

    2015-12-01

    This work was motivated by the observation, as early as 2008, that GYRO simulations of some ITER operating scenarios exhibited nonlinear zonal-flow generation large enough to effectively quench turbulence inside r /a ~ 0.5. This observation of flow-dominated, low-transport states persisted even as more accurate and comprehensive predictions of ITER profiles were made using the state-of-the-art TGLF transport model. This core stabilization is in stark contrast to GYRO-TGLF comparisons for modern-day tokamaks, for which GYRO and TGLF are typically in very close agreement. So, we began to suspect that TGLF needed to be generalized to include the effect of zonal-flow stabilization in order to be more accurate for the conditions of reactor simulations. While the precise cause of the GYRO-TGLF discrepancy for ITER parameters was not known, it was speculated that closeness to threshold in the absence of driven rotation, as well as electromagnetic stabilization, created conditions more sensitive the self-generated zonal-flow stabilization than in modern tokamaks. Need for nonlinear zonal-flow stabilization: To explore the inclusion of a zonal-flow stabilization mechanism in TGLF, we started with a nominal ITER profile predicted by TGLF, and then performed linear and nonlinear GYRO simulations to characterize the behavior at and slightly above the nominal temperature gradients for finite levels of energy transport. Then, we ran TGLF on these cases to see where the discrepancies were largest. The predicted ITER profiles were indeed near to the TGLF threshold over most of the plasma core in the hybrid discharge studied (weak magnetic shear, q > 1). Scanning temperature gradients above the TGLF power balance values also showed that TGLF overpredicted the electron energy transport in the low-collisionality ITER plasma. At first (in Q3), a model of only the zonal-flow stabilization (Dimits shift) was attempted. Although we were able to construct an ad hoc model of the zonal

  2. Impacts of pellets injected from the low-field side on plasma in ITER

    SciTech Connect (OSTI)

    Wisitsorasak, A.; Onjun, T.

    2011-01-15

    Impacts of pellets injected from the low-field side (LFS) on plasma in ITER are investigated using the 1.5D BALDUR integrated predictive modeling code. In these simulations, the pellet ablation is described using the neutral gas shielding (NGS) model. The pellet ablation model is coupled with the plasma core transport model, which is a combination of the MMM95 anomalous transport model and NCLASS neoclassical transport model. The boundary conditions are assumed to be at the top of the pedestal, in which the pedestal parameters are predicted using a pedestal model based on the theoretical-based pedestal width scaling (either magnetic and flow shear stabilization width scaling, or flow shear stabilization width scaling, or normalized poloidal pressure width scaling) and the infinite-n ballooning mode pressure gradient limit. These pedestal models depend sensitively on the density at the top of the pedestal, which can be strongly influenced by the injection of pellets. The combination of the MMM95 and NCLASS models, together with the pedestal and NGS models, is used to simulate the time evolution of the plasma current, ion and electron temperatures, and density profiles for ITER standard type-I ELMy H-mode discharges during the injection of LFS pellets. It is found that the injection of pellets results in a complicated plasma scenario, especially in the outer region of the plasma and the plasma conditions at the boundary in which the pellet has an impact on increasing the plasma edge density, but reducing the plasma edge temperature. The LFS pellet has a stronger impact on the edge as compared to the center. For fusion performance, the pellet can result in either enhancement or degradation, depending sensitively on the pellet parameters; such as the pellet size, pellet velocity, and pellet frequency. For example, when a series of deuterium pellets with a size of 0.5 cm, velocity of 1 km/s, and frequency of 2 Hz are injected into the ITER plasma from the LFS, the

  3. Convergence estimates for iterative methods via the Kriess Matrix Theorem on a general complex domain

    SciTech Connect (OSTI)

    Toh, K.C.; Trefethen, L.N.

    1994-12-31

    What properties of a nonsymmetric matrix A determine the convergence rate of iterations such as GMRES, QMR, and Arnoldi? If A is far from normal, should one replace the usual Ritz values {r_arrow} eigenvalues notion of convergence of Arnoldi by alternative notions such as Arnoldi lemniscates {r_arrow} pseudospectra? Since Krylov subspace iterations can be interpreted as minimization processes involving polynomials of matrices, the answers to questions such as these depend upon mathematical problems of the following kind. Given a polynomial p(z), how can one bound the norm of p(A) in terms of (1) the size of p(z) on various sets in the complex plane, and (2) the locations of the spectrum and pseudospectra of A? This talk reports some progress towards solving these problems. In particular, the authors present theorems that generalize the Kreiss matrix theorem from the unit disk (for the monomial A{sup n}) to a class of general complex domains (for polynomials p(A)).

  4. Fusion Materials Science and Technology Research Needs: Now and During the ITER era

    SciTech Connect (OSTI)

    Wirth, Brian D.; Kurtz, Richard J.; Snead, Lance L.

    2013-09-30

    The plasma facing components, first wall and blanket systems of future tokamak-based fusion power plants arguably represent the single greatest materials engineering challenge of all time. Indeed, the United States National Academy of Engineering has recently ranked the quest for fusion as one of the top grand challenges for engineering in the 21st Century. These challenges are even more pronounced by the lack of experimental testing facilities that replicate the extreme operating environment involving simultaneous high heat and particle fluxes, large time varying stresses, corrosive chemical environments, and large fluxes of 14-MeV peaked fusion neutrons. This paper will review, and attempt to prioritize, the materials research and development challenges facing fusion nuclear science and technology into the ITER era and beyond to DEMO. In particular, the presentation will highlight the materials degradation mechanisms we anticipate to occur in the fusion environment, the temperature- displacement goals for fusion materials and plasma facing components and the near and long-term materials challenges required for both ITER, a fusion nuclear science facility and longer term ultimately DEMO.

  5. Atomic data for the ITER Core Imaging X-ray Spectrometer (Conference...

    Office of Scientific and Technical Information (OSTI)

    Atomic data for the ITER Core Imaging X-ray Spectrometer Citation Details In-Document Search Title: Atomic data for the ITER Core Imaging X-ray Spectrometer You are accessing a ...

  6. ReNeW: Magnetic Fusion Energy Research Needs for the ITER Era...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ReNeW: Magnetic Fusion Energy Research Needs for the ITER Era Citation Details In-Document Search Title: ReNeW: Magnetic Fusion Energy Research Needs for the ITER Era Authors: ...

  7. Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT

    SciTech Connect (OSTI)

    Matenine, Dmitri Mascolo-Fortin, Julia; Goussard, Yves

    2015-11-15

    Purpose: The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. Methods: This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. Results: The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. Conclusions: The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can

  8. U.S.Statements on International Fusion Reactor (ITER) Siting Decision |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy U.S.Statements on International Fusion Reactor (ITER) Siting Decision U.S.Statements on International Fusion Reactor (ITER) Siting Decision June 28, 2005 - 1:45pm Addthis WASHINGTON, DC - Today in Moscow, Russia, the ministers representing the six ITER parties, including Dr. Raymond L. Orbach, Director of the U.S. Department of Energy's Office of Science, announced the ITER international fusion reactor will be located at the EU site in Cadarache, France. Below are

  9. An iterative particle filter approach for coupled hydro-geophysical inversion of a controlled infiltration experiment

    SciTech Connect (OSTI)

    Manoli, Gabriele; Rossi, Matteo; Pasetto, Damiano; Deiana, Rita; Ferraris, Stefano; Cassiani, Giorgio; Putti, Mario

    2015-02-15

    The modeling of unsaturated groundwater flow is affected by a high degree of uncertainty related to both measurement and model errors. Geophysical methods such as Electrical Resistivity Tomography (ERT) can provide useful indirect information on the hydrological processes occurring in the vadose zone. In this paper, we propose and test an iterated particle filter method to solve the coupled hydrogeophysical inverse problem. We focus on an infiltration test monitored by time-lapse ERT and modeled using Richards equation. The goal is to identify hydrological model parameters from ERT electrical potential measurements. Traditional uncoupled inversion relies on the solution of two sequential inverse problems, the first one applied to the ERT measurements, the second one to Richards equation. This approach does not ensure an accurate quantitative description of the physical state, typically violating mass balance. To avoid one of these two inversions and incorporate in the process more physical simulation constraints, we cast the problem within the framework of a SIR (Sequential Importance Resampling) data assimilation approach that uses a Richards equation solver to model the hydrological dynamics and a forward ERT simulator combined with Archie's law to serve as measurement model. ERT observations are then used to update the state of the system as well as to estimate the model parameters and their posterior distribution. The limitations of the traditional sequential Bayesian approach are investigated and an innovative iterative approach is proposed to estimate the model parameters with high accuracy. The numerical properties of the developed algorithm are verified on both homogeneous and heterogeneous synthetic test cases based on a real-world field experiment.

  10. Advances in the Understanding of ELM Suppression by Resonant Magnetic Perturbations (RMPs) in DIII-D and Implications for ITER

    SciTech Connect (OSTI)

    Nazikian, R.

    2014-09-01

    Experiments on DIII-D have expanding the operating window for RMP ELM suppression to higher q95 with dominant electron heating and fully non-inductive current drive relevant to advanced modes of ITER operation. Robust ELM suppression has also been obtained with a reduced coil set, mitigating the risk of coil failure in maintaining ELM suppression in ITER. These results significantly expand the operating space and reduce risk for obtaining RMP ELM suppression in ITER. Efforts have also been made to search for 3D cause of ELM suppression. No internal non-axisymmetric structure is detected at the top of the pedestal, indicating that the dominant effect of the RMP is to produce an n=0 transport modification of the profiles. Linear two fluid MHD simulations using M3D-C1 indicate resonant field penetration and significant magnetic stochasticity at the top of the pedestal, consistent with the absence of detectable 3D structure in that region. A profile database was developed to compare the scaling of the pedestal and global confinement with the applied 3D field strength in ELM suppressed and ELM mitigated plasmas. The EPED pedestal model accurately predicts the measured pedestal pressure at the threshold of ELM suppression, increasing confidence in theoretical projections to ITER pedestal conditions. Both the H-factor (H(sub)98y2) and thermal energy confinement time do not degrade substantially with applied RMP fields near the threshold of ELM suppression, enhancing confidence in the compatibility of ITER high performance operation with RMP ELM suppression.

  11. Material migration studies with an ITER first wall panel proxy on EAST

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ding, R.; Pitts, R. A.; Borodin, D.; Carpentier, S.; Ding, F.; Gong, X. Z.; Guo, H. Y.; Kirschner, A.; Kocan, M.; Li, J. G.; et al

    2015-01-23

    The ITER beryllium (Be) first wall (FW) panels are shaped to protect leading edges between neighbouring panels arising from assembly tolerances. This departure from a perfectly cylindrical surface automatically leads to magnetically shadowed regions where eroded Be can be re-deposited, together with co-deposition of tritium fuel. To provide a benchmark for a series of erosion/re-deposition simulation studies performed for the ITER FW panels, dedicated experiments have been performed on the EAST tokamak using a specially designed, instrumented test limiter acting as a proxy for the FW panel geometry. Carbon coated molybdenum plates forming the limiter front surface were exposed tomore » the outer midplane boundary plasma of helium discharges using the new Material and Plasma Evaluation System (MAPES). Net erosion and deposition patterns are estimated using ion beam analysis to measure the carbon layer thickness variation across the surface after exposure. The highest erosion of about 0.8 µm is found near the midplane, where the surface is closest to the plasma separatrix. No net deposition above the measurement detection limit was found on the proxy wall element, even in shadowed regions. The measured 2D surface erosion distribution has been modelled with the 3D Monte Carlo code ERO, using the local plasma parameter measurements together with a diffusive transport assumption. In conclusion, excellent agreement between the experimentally observed net erosion and the modelled erosion profile has been obtained.« less

  12. Material migration studies with an ITER first wall panel proxy on EAST

    SciTech Connect (OSTI)

    Ding, R.; Pitts, R. A.; Borodin, D.; Carpentier, S.; Ding, F.; Gong, X. Z.; Guo, H. Y.; Kirschner, A.; Kocan, M.; Li, J. G.; Luo, G. -N.; Mao, H. M.; Qian, J. P.; Stangeby, P. C.; Wampler, W. R.; Wang, H. Q.; Wang, W. Z.; Chen, J. L.; Gan, K. F.

    2015-01-23

    The ITER beryllium (Be) first wall (FW) panels are shaped to protect leading edges between neighbouring panels arising from assembly tolerances. This departure from a perfectly cylindrical surface automatically leads to magnetically shadowed regions where eroded Be can be re-deposited, together with co-deposition of tritium fuel. To provide a benchmark for a series of erosion/re-deposition simulation studies performed for the ITER FW panels, dedicated experiments have been performed on the EAST tokamak using a specially designed, instrumented test limiter acting as a proxy for the FW panel geometry. Carbon coated molybdenum plates forming the limiter front surface were exposed to the outer midplane boundary plasma of helium discharges using the new Material and Plasma Evaluation System (MAPES). Net erosion and deposition patterns are estimated using ion beam analysis to measure the carbon layer thickness variation across the surface after exposure. The highest erosion of about 0.8 µm is found near the midplane, where the surface is closest to the plasma separatrix. No net deposition above the measurement detection limit was found on the proxy wall element, even in shadowed regions. The measured 2D surface erosion distribution has been modelled with the 3D Monte Carlo code ERO, using the local plasma parameter measurements together with a diffusive transport assumption. In conclusion, excellent agreement between the experimentally observed net erosion and the modelled erosion profile has been obtained.

  13. Optimization studies of the ITER low field side reflectometer

    SciTech Connect (OSTI)

    Hanson, Gregory R; Wilgen, John B; Bigelow, Tim S; Diem, Stephanie J

    2010-01-01

    Microwave reflectometry will be used on ITER to measure the electron density profile, density fluctuations due to MHD/turbulence, ELM density transients, and as a L-H transition monitor. The ITER low field side (LFS) reflectometer system will measure both core and edge quantities using multiple antenna arrays spanning frequency ranges of 15-155 GHz for the O-mode system and 55-220 GHz for the X-mode system. Optimization studies using the GENRAY ray-tracing code have been done for edge and core measurements. The reflectometer launchers will utilize the HE11 mode launched from circular corrugated waveguide. The launched beams are assumed to be Gaussian with a beam waist diameter of 0.643 times the waveguide diameter. Optimum launcher size and placement are investigated by computing the antenna coupling between launchers, assuming the launched and received beams have a Gaussian beam pattern.

  14. Optimization studies of the ITER low field side reflectometer

    SciTech Connect (OSTI)

    Diem, S. J.; Wilgen, J. B.; Bigelow, T. S.; Hanson, G. R.; Harvey, R. W.; Smirnov, A. P.

    2010-10-15

    Microwave reflectometry will be used on ITER to measure the electron density profile, density fluctuations due to MHD/turbulence, edge localized mode (ELM) density transients, and as an L-H transition monitor. The ITER low field side reflectometer system will measure both core and edge quantities using multiple antenna arrays spanning frequency ranges of 15-155 GHz for the O-mode system and 55-220 GHz for the X-mode system. Optimization studies using the GENRAY ray-tracing code have been done for edge and core measurements. The reflectometer launchers will utilize the HE11 mode launched from circular corrugated waveguide. The launched beams are assumed to be Gaussian with a beam waist diameter of 0.643 times the waveguide diameter. Optimum launcher size and placement are investigated by computing the antenna coupling between launchers, assuming the launched and received beams have a Gaussian beam pattern.

  15. Qualification of the Joints for ITER Central Solenoid

    SciTech Connect (OSTI)

    Martovetsky, Nicolai N; Berryhill, Adam B; Kenney, Steven J

    2012-01-01

    The ITER Central Solenoid has 36 interpancake joints, 12 bus joints, and 12 feeder joints in the magnet. The joints are required to have resistance below 4 nOhm at 45 kA at 4.5 K. The US ITER Project Office developed two different types of interpancake joints with some variations in details in order to find a better design, qualify the joints, and establish a fabrication process. We built and tested four samples of the sintered joints and two samples with butt-bonded joints (a total of eight joints). Both designs met the specifications. Results of the joint development, test results, and selection of the baseline design are presented and discussed in the paper.

  16. P-SPARSLIB: A parallel sparse iterative solution package

    SciTech Connect (OSTI)

    Saad, Y.

    1994-12-31

    Iterative methods are gaining popularity in engineering and sciences at a time where the computational environment is changing rapidly. P-SPARSLIB is a project to build a software library for sparse matrix computations on parallel computers. The emphasis is on iterative methods and the use of distributed sparse matrices, an extension of the domain decomposition approach to general sparse matrices. One of the goals of this project is to develop a software package geared towards specific applications. For example, the author will test the performance and usefulness of P-SPARSLIB modules on linear systems arising from CFD applications. Equally important is the goal of portability. In the long run, the author wishes to ensure that this package is portable on a variety of platforms, including SIMD environments and shared memory environments.

  17. Variable frequency iteration MPPT for resonant power converters

    DOE Patents [OSTI]

    Zhang, Qian; Bataresh, Issa; Chen, Lin

    2015-06-30

    A method of maximum power point tracking (MPPT) uses an MPPT algorithm to determine a switching frequency for a resonant power converter, including initializing by setting an initial boundary frequency range that is divided into initial frequency sub-ranges bounded by initial frequencies including an initial center frequency and first and second initial bounding frequencies. A first iteration includes measuring initial powers at the initial frequencies to determine a maximum power initial frequency that is used to set a first reduced frequency search range centered or bounded by the maximum power initial frequency including at least a first additional bounding frequency. A second iteration includes calculating first and second center frequencies by averaging adjacent frequent values in the first reduced frequency search range and measuring second power values at the first and second center frequencies. The switching frequency is determined from measured power values including the second power values.

  18. Object-oriented design of preconditioned iterative methods

    SciTech Connect (OSTI)

    Bruaset, A.M.

    1994-12-31

    In this talk the author discusses how object-oriented programming techniques can be used to develop a flexible software package for preconditioned iterative methods. The ideas described have been used to implement the linear algebra part of Diffpack, which is a collection of C++ class libraries that provides high-level tools for the solution of partial differential equations. In particular, this software package is aimed at rapid development of PDE-based numerical simulators, primarily using finite element methods.

  19. International Workshop: MFE Roadmapping in the ITER Era | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab Princeton, NJ International Workshop: MFE Roadmapping in the ITER Era Princeton University Princeton, NJ Host: G.H. Neilson Coordinator: Pamela Hampton /p> Contact Information Website: Website Coordinator(s): Pamela Hampton phampton@pppl.gov Host(s): G.H. Neilson hneilson@pppl.gov PPPL Entrance Procedures Visitor Information, Directions, Security at PPPL As a federal facility, the Princeton Plasma Physics Laboratory is operating under heightened security measures because of

  20. President Bush Issues Executive Order Designating ITER International Fusion

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Energy Organization A Public Interest Organization | U.S. DOE Office of Science (SC) President Bush Issues Executive Order Designating ITER International Fusion Energy Organization A Public Interest Organization News News Home Featured Articles Science Headlines 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 Science Highlights Presentations & Testimony News Archives Communications and Public Affairs Contact Information Office of Science U.S. Department of Energy 1000

  1. Progress and present status of ITER cryoline system

    SciTech Connect (OSTI)

    Badgujar, S.; Bonneton, M.; Chalifour, M.; Forgeas, A.; Serio, L.; Sarkar, B.; Shah, N.

    2014-01-29

    The cryoline system at ITER forms a very complex network localized inside the Tokamak building, on a dedicated plant bridge and in cryoplant areas. The cooling power produced in the cryoplant is distributed via these lines with a total length of about 3.7 km and interconnecting all the cold boxes of the cryogenic system as well as the cold boxes of various clients (magnets, cryopumps and thermal shield). Distinct layouts and polygonal geometry, nuclear safety and confinement requirements, difficult installation and in-service inspection/repair demand very high reliability and availability for the cryolines. The finalization of the building-embedded plates for supporting the lines, before the detailed design, has made this project technologically more challenging. The conceptual design phase has been completed and procurement arrangements have been signed with India, responsible for providing the system of cryolines and warm lines to ITER, as in kind contribution. The prototype test for the design and performance validation has been planned on a representative cryoline section. After describing the basic features and general layout of the ITER cryolines, the paper presents key design requirements, conceptual design approach, progress and status of the cryolines project as well as challenges to build such a complex cryoline system.

  2. Qualification of the Joints for the ITER Central Solenoid

    SciTech Connect (OSTI)

    Martovetsky, N; Berryhill, A; Kenney, S

    2011-09-01

    The ITER Central Solenoid has 36 interpancake joints, 12 bus joints, and 12 feeder joints in the magnet. The joints are required to have resistance below 4 nOhm at 45 kA at 4.5 K. The US ITER Project Office developed two different types of interpancake joints with some variations in details in order to find a better design, qualify the joints, and establish a fabrication process. We built and tested four samples of the sintered joints and two samples with butt-bonded joints (a total of eight joints). Both designs met the specifications. Results of the joint development, test results, and selection of the baseline design are presented and discussed in the paper. The ITER Central Solenoid (CS) consists of six modules. Each module is composed of six wound hexapancakes and one quadrapancake. The multipancakes are connected electrically and hydraulically by in-line interpancake joints. The joints are located at the outside diameter (OD) of the module. Cable in conduit conductor (CICC) high-current joints are critical elements in the CICC magnets. In addition to low resistivity, the CS joints must fit a space envelope equivalent to the regular conductor cross section and must have low hydraulic impedance and enough structural strength to withstand the hoop and compressive forces during operation, including cycling. This paper is the continuation of the work reported on the intermodule joints.

  3. Investigation of statistical iterative reconstruction for dedicated breast CT

    SciTech Connect (OSTI)

    Makeev, Andrey; Glick, Stephen J.

    2013-08-15

    Purpose: Dedicated breast CT has great potential for improving the detection and diagnosis of breast cancer. Statistical iterative reconstruction (SIR) in dedicated breast CT is a promising alternative to traditional filtered backprojection (FBP). One of the difficulties in using SIR is the presence of free parameters in the algorithm that control the appearance of the resulting image. These parameters require tuning in order to achieve high quality reconstructions. In this study, the authors investigated the penalized maximum likelihood (PML) method with two commonly used types of roughness penalty functions: hyperbolic potential and anisotropic total variation (TV) norm. Reconstructed images were compared with images obtained using standard FBP. Optimal parameters for PML with the hyperbolic prior are reported for the task of detecting microcalcifications embedded in breast tissue.Methods: Computer simulations were used to acquire projections in a half-cone beam geometry. The modeled setup describes a realistic breast CT benchtop system, with an x-ray spectra produced by a point source and an a-Si, CsI:Tl flat-panel detector. A voxelized anthropomorphic breast phantom with 280 ?m microcalcification spheres embedded in it was used to model attenuation properties of the uncompressed woman's breast in a pendant position. The reconstruction of 3D images was performed using the separable paraboloidal surrogates algorithm with ordered subsets. Task performance was assessed with the ideal observer detectability index to determine optimal PML parameters.Results: The authors' findings suggest that there is a preferred range of values of the roughness penalty weight and the edge preservation threshold in the penalized objective function with the hyperbolic potential, which resulted in low noise images with high contrast microcalcifications preserved. In terms of numerical observer detectability index, the PML method with optimal parameters yielded substantially improved

  4. Implementation of an iterative matching scheme for the Kapchinskij-Vladimirskij equations in the WARP code

    SciTech Connect (OSTI)

    Chilton, Sven; Chilton, Sven H.

    2008-07-01

    The WARP code is a robust electrostatic particle-in-cell simulation package used to model charged particle beams with strong space-charge forces. A fundamental operation associated with seeding detailed simulations of a beam transport channel is to generate initial conditions where the beam distribution is matched to the structure of a periodic focusing lattice. This is done by solving for periodic, matched solutions to a coupled set of ODEs called the Kapchinskij-Vladimirskij (KV) envelope equations, which describe the evolution of low-order beam moments subject to applied lattice focusing, space-charge defocusing, and thermal defocusing forces. Recently, an iterative numerical method was developed (Lund, Chilton, and Lee, Efficient computation of matched solutions to the KV envelope equations for periodic focusing lattices, Physical Review Special Topics-Accelerators and Beams 9, 064201 2006) to generate matching conditions in a highly flexible, convergent, and fail-safe manner. This method is extended and implemented in the WARP code as a Python package to vastly ease the setup of detailed simulations. In particular, the Python package accommodates any linear applied lattice focusing functions without skew coupling, and a more general set of beam parameter specifications than its predecessor. Lattice strength iteration tools were added to facilitate the implementation of problems with specific applied focusing strengths.

  5. Commitment to Public Involvement

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Create a Sustainable Future » Commitment to Public Involvement Commitment to Public Involvement LANL is committed to our neighbors August 1, 2013 Lab Director McMillan talks with Lab historian Ellen McGhee during Lab tour Lab Director McMillan talks with Lab historian Ellen McGhee during Lab tour RELATED IMAGES http://farm4.staticflickr.com/3815/9442115459_390e5bc841_t.jpg Enlarge http://farm8.staticflickr.com/7111/7650961650_ed1571174f_t.jpg Enlarge

  6. Time parallelization of advanced operation scenario simulations of ITER plasma

    SciTech Connect (OSTI)

    Samaddar, D.; Casper, T. A.; Kim, S. H.; Berry, Lee A; Elwasif, Wael R; Batchelor, Donald B; Houlberg, Wayne A

    2013-01-01

    This work demonstrates that simulations of advanced burning plasma operation scenarios can be successfully parallelized in time using the parareal algorithm. CORSICA - an advanced operation scenario code for tokamak plasmas is used as a test case. This is a unique application since the parareal algorithm has so far been applied to relatively much simpler systems except for the case of turbulence. In the present application, a computational gain of an order of magnitude has been achieved which is extremely promising. A successful implementation of the Parareal algorithm to codes like CORSICA ushers in the possibility of time efficient simulations of ITER plasmas.

  7. Iterative Schemes for Time Parallelization with Application to Reservoir Simulation

    SciTech Connect (OSTI)

    Garrido, I; Fladmark, G E; Espedal, M S; Lee, B

    2005-04-18

    Parallel methods are usually not applied to the time domain because of the inherit sequentialness of time evolution. But for many evolutionary problems, computer simulation can benefit substantially from time parallelization methods. In this paper, they present several such algorithms that actually exploit the sequential nature of time evolution through a predictor-corrector procedure. This sequentialness ensures convergence of a parallel predictor-corrector scheme within a fixed number of iterations. The performance of these novel algorithms, which are derived from the classical alternating Schwarz method, are illustrated through several numerical examples using the reservoir simulator Athena.

  8. Pre-Commercial Demonstration of Direct Non-Iterative State Estimator (DNSE+)

    SciTech Connect (OSTI)

    Lelic, Dino

    2015-04-24

    The objective of this DOE co-funded project is to demonstrate functionality and performance of a production-grade Direct Non-iterative State Estimator (DNSE) through its integration with NYPA’s Energy Management System (EMS) and an enhanced Real Time Dynamics Monitoring System (RTDMS) synchrophasor platform from Electric Power Group (EPG). A production-grade DNSE aims to overcome a major obstacle to the operational use of synchrophasor data in Synchro-Phasor Management Systems (SPMS) by providing SPMS applications with a consistent and a complete synchrophasor data foundation in the same way that a traditional EMS State Estimator (SE) provides to EMS applications. Specifically, the DNSE uses synchrophasor measurements and Supervisory Control and Data Acquisition (SCADA) measurements, together with the complete power system model, to simultaneously obtain the complete state of the entire utility’s operating model at rates that are close to the synchrophasor data rates. The full system coverage property is what distinguishes the DNSE from the linear synchrophasor SEs (which cover only parts of the operating model that are visible through synchrophasor measurements), and DNSE differs from traditional EMS SE in that the solution is obtained without iterations, without initial values (hence the “direct” in the name), and at a much higher execution rate. This presentation provides an overview of the project objectives, a brief description of the main tasks including the development work to productize and optimize DNSE from its current MATLAB code base, RTDMS enhancement for interfacing with the DNSE, factory acceptance testing, field installation, testing and demonstration, as well as the current status of the project execution.

  9. Involvement and Communication Committee.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Public Involvement and Communication Committee Chair 1 : Liz Mattson 4 , Member Vice Chair 1 : Shannon Cram, Member Committee Members 2 : Shelley Cimon Paige Knight Alissa Cordner Liz Mattson Shannon Cram Ken Niles Rob Davis Ed Pacheco Tom Galioto Dan Serres Floyd Hodges Jean Vanni Unofficial Committee Members or Other Interested Parties 3 : Earl Fordham Gerry Pollet Susan Leckband 4 Steve Hudson 4 Facilitator: Cathy McCague 4 Agency & Technical Support: Kris Holmes 4 DOE-RL Randy Bradbury 4

  10. Chevron beam dump for ITER edge Thomson scattering system

    SciTech Connect (OSTI)

    Yatsuka, E.; Hatae, T.; Bassan, M.; Itami, K.; Vayakis, G.

    2013-10-15

    This paper contains the design of the beam dump for the ITER edge Thomson scattering system and mainly concerns its lifetime under the harsh thermal and electromagnetic loads as well as tight space allocation. The lifetime was estimated from the multi-pulse laser-induced damage threshold. In order to extend its lifetime, the structure of the beam dump was optimized. A number of bent sheets aligned parallel in the beam dump form a shape called a chevron which enables it to avoid the concentration of the incident laser pulse energy. The chevron beam dump is expected to withstand thermal loads due to nuclear heating, radiation from the plasma, and numerous incident laser pulses throughout the entire ITER project with a reasonable margin for the peak factor of the beam profile. Structural analysis was also carried out in case of electromagnetic loads during a disruption. Moreover, detailed issues for more accurate assessments of the beam dump's lifetime are clarified. Variation of the bi-directional reflection distribution function (BRDF) due to erosion by or contamination of neutral particles derived from the plasma is one of the most critical issues that needs to be resolved. In this paper, the BRDF was assumed, and the total amount of stray light and the absorbed laser energy profile on the beam dump were evaluated.

  11. "Progress in U.S. ITER Magnet Systems", Wayne Reiersen, Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    University | Princeton Plasma Physics Lab November 28, 2012, 4:15pm MBG Auditorium "Progress in U.S. ITER Magnet Systems", Wayne Reiersen, Princeton University Mr. Wayne Reiersen Princeton University U.S. ITER is responsible for providing the ITER Central Solenoid (CS), nine lengths of Toroidal Field (TF) Coil conductor, and Insert Coils for assessing CS and TF conductor performance. The status of the ongoing design and fabrication efforts will be reviewed. The interesting hurdles

  12. Iterative image-domain decomposition for dual-energy CT

    SciTech Connect (OSTI)

    Niu, Tianye; Dong, Xue; Petrongolo, Michael; Zhu, Lei

    2014-04-15

    Purpose: Dual energy CT (DECT) imaging plays an important role in advanced imaging applications due to its capability of material decomposition. Direct decomposition via matrix inversion suffers from significant degradation of image signal-to-noise ratios, which reduces clinical values of DECT. Existing denoising algorithms achieve suboptimal performance since they suppress image noise either before or after the decomposition and do not fully explore the noise statistical properties of the decomposition process. In this work, the authors propose an iterative image-domain decomposition method for noise suppression in DECT, using the full variance-covariance matrix of the decomposed images. Methods: The proposed algorithm is formulated in the form of least-square estimation with smoothness regularization. Based on the design principles of a best linear unbiased estimator, the authors include the inverse of the estimated variance-covariance matrix of the decomposed images as the penalty weight in the least-square term. The regularization term enforces the image smoothness by calculating the square sum of neighboring pixel value differences. To retain the boundary sharpness of the decomposed images, the authors detect the edges in the CT images before decomposition. These edge pixels have small weights in the calculation of the regularization term. Distinct from the existing denoising algorithms applied on the images before or after decomposition, the method has an iterative process for noise suppression, with decomposition performed in each iteration. The authors implement the proposed algorithm using a standard conjugate gradient algorithm. The method performance is evaluated using an evaluation phantom (Catphan600) and an anthropomorphic head phantom. The results are compared with those generated using direct matrix inversion with no noise suppression, a denoising method applied on the decomposed images, and an existing algorithm with similar formulation as the

  13. ISIS++Reference Guide (Iterative Scalable Implicit Solver in C++) Version 1.1

    SciTech Connect (OSTI)

    Alan B. Williams; Benjamin A. Allan; Kyran D. Mish; Robert L. Clay

    1999-04-01

    ISIS++ (Iterative Scalable Implicit Solver in C++) Version 1.1 is a portable, object-oriented framework for solving sparse linear systems of equations. It includes a collection of Krylov solution methods and preconditioners, as well as both uni-processor (serial) and multi-processor (scalable) matrix and vector classes. Though it was developed to solve systems of equations originating from large-scale, 3-D, finite element analyses, it has application in many other fields. This document supersedes the ISIS++ V1.0 Reference Guide, defines the V1. 1 interface specification, and includes the necessary instructions for building and running ISIS++ v 1.1 on Unix platforms. The interface is presented in annotated header format, along with background on design and implementation considerations. A finite difference modeling example problem is included to demonstrate the overall setup and use.

  14. Flow distribution analysis on the cooling tube network of ITER thermal shield

    SciTech Connect (OSTI)

    Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun; Kang, Dong Kwon; Kang, Kyoung-O; Ahn, Hee Jae; Lee, Hyeon Gon

    2014-01-29

    Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube network for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.

  15. Advancing the Physics Basis of Quiescent H-mode through Exploration of ITER Relevant Parameters

    SciTech Connect (OSTI)

    Solomon, W. M.; Burrell, K. H.; Fenstermacher, M. E.; Garofalo, A. M.; Grierson, B. A.; Loarte, A.; McKee, G. R.; Nazikian, R.; Snyder, B. P.

    2014-09-01

    Recent experiments on DIII-D have overcome a long-standing limitation in accessing quiescent H-mode (QH-mode), a high confinement state of the plasma that does not exhibit the explosive instabilities associated with edge localized modes (ELMs). In the past, QH-mode was associated with low density operation, but has now been extended to high normalized densities compatible with operation envisioned for ITER. Through the use of strong shaping, QH-mode plasmas have been maintained at high densities, both absolute (?e ? 7 1019 m3) and normalized Greenwald fraction (?e/?G > 0:7) . In these plasmas, the pedestal can evolve to very high pressures and current as the density is increased. Calculations of the pedestal height and width from the EPED model are quantitatively consistent with the experimental observed evolution with density. The comparison of the dependence of the maximum density threshold for QH-mode with plasma shape help validate the underlying theoretical peeling-ballooning models describing ELM stability. High density QH-mode operation with strong shaping has allowed stable access to a previously predicted regime of very high pedestal dubbed \\Super H-mode". In general, QH-mode is found to achieve ELM-stable operation while maintaining adequate impurity exhaust, due to the enhanced impurity transport from an edge harmonic oscillation, thought to be a saturated kink- peeling mode driven by rotation shear. In addition, the impurity confinement time is not affected by rotation, even though the energy confinement time and measured E ? B shear is observed to increase at low toroidal rotation. Together with demonstrations of high beta, high confinement and low q95 for many energy confinement times, these results suggest QH-mode as a potentially attractive operating scenario for ITER's Q=10 mission.

  16. The high-β{sub N} hybrid scenario for ITER and FNSF steady-state missions

    SciTech Connect (OSTI)

    Turco, F.; Petty, C. C.; Luce, T. C.; Carlstrom, T. N.; Van Zeeland, M. A.; Ferron, J. R.; Heidbrink, W.; Carpanese, F.; Holcomb, C. T.

    2015-05-15

    New experiments on DIII-D have demonstrated the steady-state potential of the hybrid scenario, with 1 MA of plasma current driven fully non-inductively and β{sub N} up to 3.7 sustained for ∼3 s (∼1.5 current diffusion time, τ{sub R}, in DIII-D), providing the basis for an attractive option for steady-state operation in ITER and FNSF. Excellent confinement is achieved (H{sub 98y2} ∼ 1.6) without performance limiting tearing modes. The hybrid regime overcomes the need for off-axis current drive efficiency, taking advantage of poloidal magnetic flux pumping that is believed to be the result of a saturated 3/2 tearing mode. This allows for efficient current drive close to the axis, without deleterious sawtooth instabilities. In these experiments, the edge surface loop voltage is driven down to zero for >1 τ{sub R} when the poloidal β is increased above 1.9 at a plasma current of 1.0 MA and the ECH power is increased to 3.2 MW. Stationary operation of hybrid plasmas with all on-axis current drive is sustained at pressures slightly above the ideal no-wall limit, while the calculated ideal with-wall MHD limit is β{sub N} ∼ 4–4.5. Off-axis Neutral Beam Injection (NBI) power has been used to broaden the pressure and current profiles in this scenario, seeking to take advantage of higher predicted kink stability limits and lower values of the tearing stability index Δ′, as calculated by the DCON and PEST3 codes. Results based on measured profiles predict ideal limits at β{sub N} > 4.5, 10% higher than the cases with on-axis NBI. A 0-D model, based on the present confinement, β{sub N} and shape values of the DIII-D hybrid scenario, shows that these plasmas are consistent with the ITER 9 MA, Q = 5 mission and the FNSF 6.7 MA scenario with Q = 3.5. With collisionality and edge safety factor values comparable to those envisioned for ITER and FNSF, the high-β{sub N} hybrid represents an attractive high performance option for the steady

  17. Thermo-mechanical analysis of ITER first mirrors and its use for the ITER equatorial visible/infrared wide angle viewing system optical design

    SciTech Connect (OSTI)

    Joanny, M.; Salasca, S.; Dapena, M.; Cantone, B.; Travere, J. M.; Thellier, C.; Ferme, J. J.; Marot, L.; Buravand, O.; Perrollaz, G.; Zeile, C.

    2012-10-15

    ITER first mirrors (FMs), as the first components of most ITER optical diagnostics, will be exposed to high plasma radiation flux and neutron load. To reduce the FMs heating and optical surface deformation induced during ITER operation, the use of relevant materials and cooling system are foreseen. The calculations led on different materials and FMs designs and geometries (100 mm and 200 mm) show that the use of CuCrZr and TZM, and a complex integrated cooling system can limit efficiently the FMs heating and reduce their optical surface deformation under plasma radiation flux and neutron load. These investigations were used to evaluate, for the ITER equatorial port visible/infrared wide angle viewing system, the impact of the FMs properties change during operation on the instrument main optical performances. The results obtained are presented and discussed.

  18. A turbulent transport network model in MULTIFLUX coupled with TOUGH2

    SciTech Connect (OSTI)

    Danko, G.; Bahrami, D.; Birkholzer, J.T.

    2011-02-15

    A new numerical method is described for the fully iterated, conjugate solution of two discrete submodels, involving (a) a transport network model for heat, moisture, and airflows in a high-permeability, air-filled cavity; and (b) a variably saturated fractured porous medium. The transport network submodel is an integrated-parameter, computational fluid dynamics solver, describing the thermal-hydrologic transport processes in the flow channel system of the cavity with laminar or turbulent flow and convective heat and mass transport, using MULTIFLUX. The porous medium submodel, using TOUGH2, is a solver for the heat and mass transport in the fractured rock mass. The new model solution extends the application fields of TOUGH2 by integrating it with turbulent flow and transport in a discrete flow network system. We present demonstrational results for a nuclear waste repository application at Yucca Mountain with the most realistic model assumptions and input parameters including the geometrical layout of the nuclear spent fuel and waste with variable heat load for the individual containers. The MULTIFLUX and TOUGH2 model elements are fully iterated, applying a programmed reprocessing of the Numerical Transport Code Functionalization model-element in an automated Outside Balance Iteration loop. The natural, convective airflow field and the heat and mass transport in a representative emplacement drift during postclosure are explicitly solved in the new model. The results demonstrate that the direction and magnitude of the air circulation patterns and all transport modes are strongly affected by the heat and moisture transport processes in the surrounding rock, justifying the need for a coupled, fully iterated model solution such as the one presented in the paper.

  19. Iterative methods for dose reduction and image enhancement in tomography

    DOE Patents [OSTI]

    Miao, Jianwei; Fahimian, Benjamin Pooya

    2012-09-18

    A system and method for creating a three dimensional cross sectional image of an object by the reconstruction of its projections that have been iteratively refined through modification in object space and Fourier space is disclosed. The invention provides systems and methods for use with any tomographic imaging system that reconstructs an object from its projections. In one embodiment, the invention presents a method to eliminate interpolations present in conventional tomography. The method has been experimentally shown to provide higher resolution and improved image quality parameters over existing approaches. A primary benefit of the method is radiation dose reduction since the invention can produce an image of a desired quality with a fewer number projections than seen with conventional methods.

  20. Thermoelectric power of supported graphene - An iterative approach

    SciTech Connect (OSTI)

    Rizwana Begum, K.; Sankeshwar, N. S.

    2015-06-24

    Thermoelectric power, S, of graphene supported on SiO{sub 2} substrate is studied for 10K < T < 400K within the framework of Boltzmann transport formalism by an iterative method. Numerical calculations of diffusion thermopower, S{sub d}, as a function of temperature, are presented assuming the electrons to be scattered by impurities, vacancies, surface roughness, acoustic phonons, inelastic optical phonons and surface polar optical phonons. For the range of temperatures considered, S{sub d} is found to be dominated by impurities for T < 40K and by acoustic phonon and vacancy scatterings for T > 40K. The optical phonons are found to influence S{sub d} for T > 300K. Our calculations, assuming the drag component to be negligible, obtain good agreement with the recent experimental data.

  1. Development of the bus joint for the ITER Central Solenoid

    SciTech Connect (OSTI)

    Martovetsky, Nicolai N; Irick, David Kim; Kenney, Steven J

    2013-01-01

    The terminations of the Central Solenoid (CS) modules are connected to the bus extensions by joints located outside the CS in the gap between the CS and Torodial Field (TF) assemblies. These joints have very strict space limitations. Low resistance is a common requirement for all ITER joints. In addition, the CS bus joints will experience and must be designed to withstand significant variation in the magnetic field of several tenths of a Tesla per second during initiation of plasma. The joint resistance is specified to be less than 4 nOhm. The joints also have to be soldered in the field and designed with the possibility to be installed and dismantled in order to allow cold testing in the cold test facility. We have developed coaxial joints that meet these requirements and have demonstrated the feasibility to fabricate and assemble them in the vertical configuration. We introduced a coupling cylinder with superconducting strands soldered to the surface of the cable that can be installed in the ITER assembly hall and at the Cold Test Facility. This cylinder serves as a transition area between the CS module and the bus extension. We made two racetrack samples and tested four bus joints in our Joint Test Apparatus. Resistance of the bus joints was measured by a decay method and by a microvoltmeter; the value of the current was measured by the Hall probes. This measurement method was verified in the previous tests. The resistance of the joints varied insignificantly from 1.5 to 2 nOhm. One of the challenges associated with a soldered joint is the inability to use corrosive chemicals that are difficult to clean. This paper describes our development work on cable preparation, chrome removal, compaction, soldering, and final assembly and presents the test results.

  2. GPU-accelerated regularized iterative reconstruction for few-view cone beam CT

    SciTech Connect (OSTI)

    Matenine, Dmitri; Goussard, Yves

    2015-04-15

    Purpose: The present work proposes an iterative reconstruction technique designed for x-ray transmission computed tomography (CT). The main objective is to provide a model-based solution to the cone-beam CT reconstruction problem, yielding accurate low-dose images via few-views acquisitions in clinically acceptable time frames. Methods: The proposed technique combines a modified ordered subsets convex (OSC) algorithm and the total variation minimization (TV) regularization technique and is called OSC-TV. The number of subsets of each OSC iteration follows a reduction pattern in order to ensure the best performance of the regularization method. Considering the high computational cost of the algorithm, it is implemented on a graphics processing unit, using parallelization to accelerate computations. Results: The reconstructions were performed on computer-simulated as well as human pelvic cone-beam CT projection data and image quality was assessed. In terms of convergence and image quality, OSC-TV performs well in reconstruction of low-dose cone-beam CT data obtained via a few-view acquisition protocol. It compares favorably to the few-view TV-regularized projections onto convex sets (POCS-TV) algorithm. It also appears to be a viable alternative to full-dataset filtered backprojection. Execution times are of 1–2 min and are compatible with the typical clinical workflow for nonreal-time applications. Conclusions: Considering the image quality and execution times, this method may be useful for reconstruction of low-dose clinical acquisitions. It may be of particular benefit to patients who undergo multiple acquisitions by reducing the overall imaging radiation dose and associated risks.

  3. Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna

    SciTech Connect (OSTI)

    Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M.

    2011-12-23

    RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

  4. Total-system performance assessment for Yucca Mountain -- SNL second iteration (TSPA-1993); Executive summary

    SciTech Connect (OSTI)

    Wilson, M.L.; Barnard, R.W.; Gauthier, J.H. |

    1994-04-01

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone. Probabilistic analyses are performed for aqueous and gaseous flow and transport, human intrusion, and basaltic magmatic activity. Results of the calculations lead to a number of recommendations concerning studies related to site characterization. Primary among these are the recommendations to obtain better information on percolation flux at Yucca Mountain, on the presence or absence of flowing fractures, and on physical and chemical processes influencing gaseous flow. Near-field thermal and chemical processes, and waste-container degradation are also areas where additional investigations may reduce important uncertainties. Recommendations for repository and waste-package design studies are: (1) to evaluate the performance implications of large-size containers, and (2) to investigate in more detail the implications of high repository thermal power output on the adjacent host rock and on the spent fuel.

  5. Computational and human observer image quality evaluation of low dose, knowledge-based CT iterative reconstruction

    SciTech Connect (OSTI)

    Eck, Brendan L.; Fahmi, Rachid; Miao, Jun; Brown, Kevin M.; Zabic, Stanislav; Raihani, Nilgoun; Wilson, David L.

    2015-10-15

    Purpose: Aims in this study are to (1) develop a computational model observer which reliably tracks the detectability of human observers in low dose computed tomography (CT) images reconstructed with knowledge-based iterative reconstruction (IMR™, Philips Healthcare) and filtered back projection (FBP) across a range of independent variables, (2) use the model to evaluate detectability trends across reconstructions and make predictions of human observer detectability, and (3) perform human observer studies based on model predictions to demonstrate applications of the model in CT imaging. Methods: Detectability (d′) was evaluated in phantom studies across a range of conditions. Images were generated using a numerical CT simulator. Trained observers performed 4-alternative forced choice (4-AFC) experiments across dose (1.3, 2.7, 4.0 mGy), pin size (4, 6, 8 mm), contrast (0.3%, 0.5%, 1.0%), and reconstruction (FBP, IMR), at fixed display window. A five-channel Laguerre–Gauss channelized Hotelling observer (CHO) was developed with internal noise added to the decision variable and/or to channel outputs, creating six different internal noise models. Semianalytic internal noise computation was tested against Monte Carlo and used to accelerate internal noise parameter optimization. Model parameters were estimated from all experiments at once using maximum likelihood on the probability correct, P{sub C}. Akaike information criterion (AIC) was used to compare models of different orders. The best model was selected according to AIC and used to predict detectability in blended FBP-IMR images, analyze trends in IMR detectability improvements, and predict dose savings with IMR. Predicted dose savings were compared against 4-AFC study results using physical CT phantom images. Results: Detection in IMR was greater than FBP in all tested conditions. The CHO with internal noise proportional to channel output standard deviations, Model-k4, showed the best trade-off between fit

  6. Questions and answers about ITER and fusion energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... The project, which involves China, the European Union, India, Japan, South Korea, Russia, and the United States, is sited in France with components contributed by all partners. ...

  7. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography

    SciTech Connect (OSTI)

    Saha, Krishnendu; Straus, Kenneth J.; Glick, Stephen J.; Chen, Yu.

    2014-08-28

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.

  8. Status of the design of the ITER ECE diagnostic

    SciTech Connect (OSTI)

    Taylor, G.; Austin, M. E.; Beno, J. H.; Danani, S.; Feder, R.; Hesler, J. L.; Hubbard, A. E.; Johnson, D. W.; Kumar, R.; Pandya, H. K. B.; Roman, C.; Rowan, W. L.; Udintsev, V.; Vayakis, G.; Walsh, M.; Kubo, S.

    2015-03-12

    In this study, the baseline design for the ITER electron cyclotron emission (ECE) diagnostic has entered the detailed preliminary design phase. Two plasma views are planned, a radial view and an oblique view that is sensitive to distortions in the electron momentum distribution near the average thermal momentum. Both views provide high spatial resolution electron temperature profiles when the momentum distribution remains Maxwellian. The ECE diagnostic system consists of the front-end optics, including two 1000 K calibration sources, in equatorial port plug EP9, the 70-1000 GHz transmission system from the front-end to the diagnostics hall, and the ECE instrumentation in the diagnostics hall. The baseline ECE instrumentation will include two Michelson interferometers that can simultaneously measure ordinary and extraordinary mode ECE from 70 to 1000 GHz, and two heterodyne radiometer systems, covering 122-230 GHz and 244-355 GHz. Significant design challenges include 1) developing highly-reliable 1000 K calibration sources and the associated shutters/mirrors, 2) providing compliant couplings between the front-end optics and the polarization splitter box that accommodate displacements of the vacuum vessel during plasma operations and bake out, 3) protecting components from damage due to stray ECH radiation and other intense millimeter wave emission and 4) providing the low-loss broadband transmission system.

  9. Status of the design of the ITER ECE diagnostic

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Taylor, G.; Austin, M. E.; Beno, J. H.; Danani, S.; Ellis, R. F.; Feder, R.; Hesler, J. L.; Hubbard, A. E.; Johnson, D. W.; Kumar, R.; et al

    2015-03-12

    In this study, the baseline design for the ITER electron cyclotron emission (ECE) diagnostic has entered the detailed preliminary design phase. Two plasma views are planned, a radial view and an oblique view that is sensitive to distortions in the electron momentum distribution near the average thermal momentum. Both views provide high spatial resolution electron temperature profiles when the momentum distribution remains Maxwellian. The ECE diagnostic system consists of the front-end optics, including two 1000 K calibration sources, in equatorial port plug EP9, the 70-1000 GHz transmission system from the front-end to the diagnostics hall, and the ECE instrumentation inmore » the diagnostics hall. The baseline ECE instrumentation will include two Michelson interferometers that can simultaneously measure ordinary and extraordinary mode ECE from 70 to 1000 GHz, and two heterodyne radiometer systems, covering 122-230 GHz and 244-355 GHz. Significant design challenges include 1) developing highly-reliable 1000 K calibration sources and the associated shutters/mirrors, 2) providing compliant couplings between the front-end optics and the polarization splitter box that accommodate displacements of the vacuum vessel during plasma operations and bake out, 3) protecting components from damage due to stray ECH radiation and other intense millimeter wave emission and 4) providing the low-loss broadband transmission system.« less

  10. Compatibility of ITER candidate materials with static gallium

    SciTech Connect (OSTI)

    Luebbers, P.R.; Chopra, O.K.

    1995-09-01

    Corrosion tests have been conducted to determine the compatibility of gallium with candidate structural materials for the International Thermonuclear Experimental Reactor (ITER) first wall/blanket systems, e.g., Type 316 stainless steel (SS), Inconel 625, and Nb-5 Mo-1 Zr. The results indicate that Type 316 SS is least resistant to corrosion in static gallium and Nb-5 Mo-1 Zr alloy is most resistant. At 400 C, corrosion rates for Type 316 SS, Inconel 625, and Nb-5 Mo-1 Zr alloy are {approx} 4.0, 0.5, and 0.03 mm/yr, respectively. Iron, nickel, and chromium react rapidly with gallium. Iron shows greater corrosion than nickel at 400 C ({ge} 88 and 18 mm/yr, respectively). The present study indicates that at temperatures up to 400 C, corrosion occurs primarily by dissolution and is accompanied by formation of metal/gallium intermetallic compounds. The growth of intermetallic compounds may control the overall rate of corrosion.

  11. Microsoft Word - Second_ ITER Council Press Release.doc | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Second_ ITER Council Press Release.doc Microsoft Word - Second_ ITER Council Press Release.doc Microsoft Word - Second_ ITER Council Press Release.doc (123.14 KB) More Documents & Publications Before the House Subcommittee on Energy - Committee on Science, Space, and Technology Joint Statement by Energy Ministers of G8, The People's Republic of China, India and The Republic of Korea (June 2008) Joint Statement by Energy Ministers of G8, The People's Republic of China, India and

  12. Formation and Sustainment of ITPs in ITER with the Baseline Heating Mix

    SciTech Connect (OSTI)

    Francesca M. Poli and Charles Kessel

    2012-12-03

    Plasmas with internal transport barriers (ITBs) are a potential and attractive route to steady-state operation in ITER. These plasmas exhibit radially localized regions of improved con nement with steep pressure gradients in the plasma core, which drive large bootstrap current and generate hollow current pro les and negative shear. This work examines the formation and sustainment of ITBs in ITER with electron cyclotron heating and current drive. It is shown that, with a trade-o of the power delivered to the equatorial and to the upper launcher, the sustainment of steady-state ITBs can be demonstrated in ITER with the baseline heating con guration.

  13. Tungsten impurity transport experiments in Alcator C-Mod to address high priority research and development for ITER

    SciTech Connect (OSTI)

    Loarte, A.; Polevoi, A. R.; Hosokawa, M.; Reinke, M. L.; Chilenski, M.; Howard, N.; Hubbard, A.; Hughes, J. W.; Rice, J. E.; Walk, J.; Köchl, F.; Pütterich, T.; Dux, R.; Zhogolev, V. E.

    2015-05-15

    Experiments in Alcator C-Mod tokamak plasmas in the Enhanced D-alpha H-mode regime with ITER-like mid-radius plasma density peaking and Ion Cyclotron Resonant heating, in which tungsten is introduced by the laser blow-off technique, have demonstrated that accumulation of tungsten in the central region of the plasma does not take place in these conditions. The measurements obtained are consistent with anomalous transport dominating tungsten transport except in the central region of the plasma where tungsten transport is neoclassical, as previously observed in other devices with dominant neutral beam injection heating, such as JET and ASDEX Upgrade. In contrast to such results, however, the measured scale lengths for plasma temperature and density in the central region of these Alcator C-Mod plasmas, with density profiles relatively flat in the core region due to the lack of core fuelling, are favourable to prevent inter and intra sawtooth tungsten accumulation in this region under dominance of neoclassical transport. Simulations of ITER H-mode plasmas, including both anomalous (modelled by the Gyro-Landau-Fluid code GLF23) and neoclassical transport for main ions and tungsten and with density profiles of similar peaking to those obtained in Alcator C-Mod show that accumulation of tungsten in the central plasma region is also unlikely to occur in stationary ITER H-mode plasmas due to the low fuelling source by the neutral beam injection (injection energy ∼ 1 MeV), which is in good agreement with findings in the Alcator C-Mod experiments.

  14. Total-system performance assessment for Yucca Mountain - SNL second iteration (TSPA-1993); Volume 2

    SciTech Connect (OSTI)

    Wilson, M.L.; Barnard, R.W.; Barr, G.E.; Dockery, H.A.; Dunn, E.; Eaton, R.R.; Martinez, M.J.; Gauthier, J.H.; Guerin, D.C.; Lu, N.

    1994-04-01

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). These analyses estimate the future behavior of a potential repository for high-level nuclear waste at the Yucca Mountain, Nevada, site under consideration by the Department of Energy. TSPA-93 builds upon previous efforts by emphasizing YMP concerns relating to site characterization, design, and regulatory compliance. Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. Hydrologic parameters and parameter probability distributions have been derived from available site data. Possible future climate changes are modeled by considering two separate groundwater infiltration conditions: {open_quotes}wet{close_quotes} with a mean flux of 10 mm/yr, and {open_quotes}dry{close_quotes} with a mean flux of 0.5 mm/yr. Two alternative waste-package designs and two alternative repository areal thermal power densities are investigated. One waste package is a thin-wall container emplaced in a vertical borehole, and the second is a container designed with corrosion-resistant and corrosion-allowance walls emplaced horizontally in the drift. Thermal power loadings of 57 kW/acre (the loading specified in the original repository conceptual design) and 114 kW/acre (a loading chosen to investigate effects of a {open_quotes}hot repository{close_quotes}) are considered. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone.

  15. Total-system performance assessment for Yucca Mountain - SNL second iteration (TSPA-1993); Volume 1

    SciTech Connect (OSTI)

    Wilson, M.L.; Gauthier, J.H.; Barnard, R.W.; Barr, G.E.; Dockery, H.A.; Dunn, E.; Eaton, R.R.; Guerin, D.C.; Lu, N.; Martinez, M.J.

    1994-04-01

    Sandia National Laboratories has completed the second iteration of the periodic total-system performance assessments (TSPA-93) for the Yucca Mountain Site Characterization Project (YMP). These analyses estimate the future behavior of a potential repository for high-level nuclear waste at the Yucca Mountain, Nevada, site under consideration by the Department of Energy. TSPA-93 builds upon previous efforts by emphasizing YMP concerns relating to site characterization, design, and regulatory compliance. Scenarios describing expected conditions (aqueous and gaseous transport of contaminants) and low-probability events (human-intrusion drilling and volcanic intrusion) are modeled. The hydrologic processes modeled include estimates of the perturbations to ambient conditions caused by heating of the repository resulting from radioactive decay of the waste. Hydrologic parameters and parameter probability distributions have been derived from available site data. Possible future climate changes are modeled by considering two separate groundwater infiltration conditions: {open_quotes}wet{close_quotes} with a mean flux of 10 mm/yr, and {open_quotes}dry{close_quotes} with a mean flux of 0.5 mm/yr. Two alternative waste-package designs and two alternative repository areal thermal power densities are investigated. One waste package is a thin-wall container emplaced in a vertical borehole, and the second is a container designed with corrosion-resistant and corrosion-allowance walls emplaced horizontally in the drift. Thermal power loadings of 57 kW/acre (the loading specified in the original repository conceptual design) and 114 kW/acre (a loading chosen to investigate effects of a {open_quotes}hot repository{close_quotes}) are considered. TSPA-93 incorporates significant new detailed process modeling, including two- and three-dimensional modeling of thermal effects, groundwater flow in the saturated-zone aquifers, and gas flow in the unsaturated zone.

  16. Final Report on ORDER No. 5312-20110620-JOHNSON-01ITER: Core...

    Office of Scientific and Technical Information (OSTI)

    Design Review Support Citation Details In-Document Search Title: Final Report on ORDER No. 5312-20110620-JOHNSON-01ITER: Core Imaging X-Ray Spectrometer Conceptual Design ...

  17. Advancements and performance of iterative methods in industrial applications codes on CRAY parallel/vector supercomputers

    SciTech Connect (OSTI)

    Poole, G.; Heroux, M.

    1994-12-31

    This paper will focus on recent work in two widely used industrial applications codes with iterative methods. The ANSYS program, a general purpose finite element code widely used in structural analysis applications, has now added an iterative solver option. Some results are given from real applications comparing performance with the tradition parallel/vector frontal solver used in ANSYS. Discussion of the applicability of iterative solvers as a general purpose solver will include the topics of robustness, as well as memory requirements and CPU performance. The FIDAP program is a widely used CFD code which uses iterative solvers routinely. A brief description of preconditioners used and some performance enhancements for CRAY parallel/vector systems is given. The solution of large-scale applications in structures and CFD includes examples from industry problems solved on CRAY systems.

  18. Final Report on ORDER No. 5312-20110620-JOHNSON-01ITER: Core...

    Office of Scientific and Technical Information (OSTI)

    Core Imaging X-Ray Spectrometer Conceptual Design Review Support Citation Details In-Document Search Title: Final Report on ORDER No. 5312-20110620-JOHNSON-01ITER: Core ...

  19. during the ITER era S.J. Zinkle; J.P. Planchard; R.W. Callis...

    Office of Scientific and Technical Information (OSTI)

    Fusion materials science and technology research opportunities now and during the ITER era S.J. Zinkle; J.P. Planchard; R.W. Callis; C.E. Kessel; P.J. Lee; K.A. McCarty; Various...

  20. ITER (International Thermonuclear Experimental Reactor) shield and blanket work package report

    SciTech Connect (OSTI)

    Not Available

    1988-06-01

    This report summarizes nuclear-related work in support of the US effort for the International Thermonuclear Experimental Reactor (ITER) Study. The purpose of this work was to prepare for the first international ITER workshop devoted to defining a basic ITER concept that will serve as a basis for an indepth conceptual design activity over the next 2-1/2 years. Primary tasks carried out during the past year included: design improvements of the inboard shield developed for the TIBER concept, scoping studies of a variety of tritium breeding blanket options, development of necessary design guidelines and evaluation criteria for the blanket options, further safety considerations related to nuclear components and issues regarding structural materials for an ITER device. 44 refs., 31 figs., 29 tabs.

  1. PPPL and ITER: Lab teams support the world's largest fusion experiment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The United States participates in ITER together with China, the European Union, India, Japan, South Korea and Russia. "It is very exciting to work on such a challenging global ...

  2. A component analysis based on serial results analyzing performance of parallel iterative programs

    SciTech Connect (OSTI)

    Richman, S.C.

    1994-12-31

    This research is concerned with the parallel performance of iterative methods for solving large, sparse, nonsymmetric linear systems. Most of the iterative methods are first presented with their time costs and convergence rates examined intensively on sequential machines, and then adapted to parallel machines. The analysis of the parallel iterative performance is more complicated than that of serial performance, since the former can be affected by many new factors, such as data communication schemes, number of processors used, and Ordering and mapping techniques. Although the author is able to summarize results from data obtained after examining certain cases by experiments, two questions remain: (1) How to explain the results obtained? (2) How to extend the results from the certain cases to general cases? To answer these two questions quantitatively, the author introduces a tool called component analysis based on serial results. This component analysis is introduced because the iterative methods consist mainly of several basic functions such as linked triads, inner products, and triangular solves, which have different intrinsic parallelisms and are suitable for different parallel techniques. The parallel performance of each iterative method is first expressed as a weighted sum of the parallel performance of the basic functions that are the components of the method. Then, one separately examines the performance of basic functions and the weighting distributions of iterative methods, from which two independent sets of information are obtained when solving a given problem. In this component approach, all the weightings require only serial costs not parallel costs, and each iterative method for solving a given problem is represented by its unique weighting distribution. The information given by the basic functions is independent of iterative method, while that given by weightings is independent of parallel technique, parallel machine and number of processors.

  3. Qualification of the US made conductors for ITER TF magnet system

    SciTech Connect (OSTI)

    Martovetsky, N; Hatfield, D; Miller, J; Bruzzone, P; Stepanov, B; Seber, B

    2009-10-08

    The US Domestic Agency (USDA) is one of the six suppliers of the TF conductor for ITER. In order to qualify conductors according to ITER requirements we prepared several lengths of the CICC and short samples for testing in the SULTAN facility in CRPP, Switzerland. We also fully characterized the strands that were used in these SULTAN samples. Fabrication experience and test results are presented and discussed.

  4. Qualification of the US Made Conductors for ITER TF Magnet System

    SciTech Connect (OSTI)

    Martovetsky, Nicolai N; Hatfield, Daniel R; Miller, John R; Bruzzone, P.; Stepanov, B.; Seber, B.

    2010-01-01

    The US Domestic Agency (USDA) is one of the six suppliers of the TF conductor for ITER. In order to qualify conductors according to ITER requirements we prepared several lengths of the CICC and short samples for testing in the SULTAN facility in CRPP, Switzerland. We also fully characterized the strands that were used in these SULTAN samples. Fabrication experience and test results are presented and discussed.

  5. The motional Stark effect diagnostic for ITER using a line-shift approach

    SciTech Connect (OSTI)

    Foley, E. L.; Levinton, F. M.; Yuh, H. Y.; Zakharov, L. E.

    2008-10-15

    The United States has been tasked with the development and implementation of a motional Stark effect (MSE) system on ITER. In the harsh ITER environment, MSE is particularly susceptible to degradation, as it depends on polarimetry, and the polarization reflection properties of surfaces are highly sensitive to thin film effects due to plasma deposition and erosion of a first mirror. Here we present the results of a comprehensive study considering a new MSE-based approach to internal plasma magnetic field measurements for ITER. The proposed method uses the line shifts in the MSE spectrum (MSE-LS) to provide a radial profile of the magnetic field magnitude. To determine the utility of MSE-LS for equilibrium reconstruction, studies were performed using the ESC-ERV code system. A near-term opportunity to test the use of MSE-LS for equilibrium reconstruction is being pursued in the implementation of MSE with laser-induced fluorescence on NSTX. Though the field values and beam energies are very different from ITER, the use of a laser allows precision spectroscopy with a similar ratio of linewidth to line spacing on NSTX as would be achievable with a passive system on ITER. Simulation results for ITER and NSTX are presented, and the relative merits of the traditional line polarization approach and the new line-shift approach are discussed.

  6. Development of a spatially resolving x-ray crystal spectrometer for measurement of ion-temperature (T{sub i}) and rotation-velocity (v) profiles in ITER

    SciTech Connect (OSTI)

    Hill, K. W.; Bitter, M.; Delgado-Aparicio, L.; Johnson, D.; Feder, R.; Beiersdorfer, P.; Dunn, J.; Morris, K.; Wang, E.; Reinke, M.; Podpaly, Y.; Rice, J. E.; Barnsley, R.; O'Mullane, M.; Lee, S. G.

    2010-10-15

    Imaging x-ray crystal spectrometer (XCS) arrays are being developed as a US-ITER activity for Doppler measurement of T{sub i} and v profiles of impurities (W, Kr, and Fe) with {approx}7 cm (a/30) and 10-100 ms resolution in ITER. The imaging XCS, modeled after a prototype instrument on Alcator C-Mod, uses a spherically bent crystal and 2D x-ray detectors to achieve high spectral resolving power (E/dE>6000) horizontally and spatial imaging vertically. Two arrays will measure T{sub i} and both poloidal and toroidal rotation velocity profiles. The measurement of many spatial chords permits tomographic inversion for the inference of local parameters. The instrument design, predictions of performance, and results from C-Mod are presented.

  7. Development of a Spatially Resolving X-Ray Crystal Spectrometer (XCS) for Measurement of Ion-Temperature (Ti) and Rotation-Velocity (v) Profiles in ITER

    SciTech Connect (OSTI)

    Hill, K W; Delgado-Aprico, L; Johnson, D; Feder, R; Beiersdorfer,; Dunn, J; Morris, K; Wang, E; Reinke, M; Podpaly, Y; Rice, J E; Barnsley, R; O'Mullane, M; Lee, S G

    2010-05-21

    Imaging XCS arrays are being developed as a US-ITER activity for Doppler measurement of Ti and v profiles of impurities (W, Kr, Fe) with ~7 cm (a/30) and 10-100 ms resolution in ITER. The imaging XCS, modeled after a PPPL-MIT instrument on Alcator C-Mod, uses a spherically bent crystal and 2d x-ray detectors to achieve high spectral resolving power (E/dE>6000) horizontally and spatial imaging vertically. Two arrays will measure Ti and both poloidal and toroidal rotation velocity profiles. Measurement of many spatial chords permits tomographic inversion for inference of local parameters. The instrument design, predictions of performance, and results from C-Mod will be presented.

  8. Numerical Analysis of Coolant Flow and Heat Transfer in ITER Diagnostic First Wall

    SciTech Connect (OSTI)

    Khodak, A.; Loesser, G.; Zhai, Y.; Udintsev, V.; Klabacha, J.; Wang, W.; Johnson, D.; Feder, R.

    2015-07-24

    We performed numerical simulations of the ITER Diagnostic First Wall (DFW) using ANSYS workbench. During operation DFW will include solid main body as well as liquid coolant. Thus thermal and hydraulic analysis of the DFW was performed using conjugated heat transfer approach, in which heat transfer was resolved in both solid and liquid parts, and simultaneously fluid dynamics analysis was performed only in the liquid part. This approach includes interface between solid and liquid part of the systemAnalysis was performed using ANSYS CFX software. CFX software allows solution of heat transfer equations in solid and liquid part, and solution of the flow equations in the liquid part. Coolant flow in the DFW was assumed turbulent and was resolved using Reynolds averaged Navier-Stokes equations with Shear Stress Transport turbulence model. Meshing was performed using CFX method available within ANSYS. The data cloud for thermal loading consisting of volumetric heating and surface heating was imported into CFX Volumetric heating source was generated using Attila software. Surface heating was obtained using radiation heat transfer analysis. Our results allowed us to identify areas of excessive heating. Proposals for cooling channel relocation were made. Additional suggestions were made to improve hydraulic performance of the cooling system.

  9. Numerical Analysis of Coolant Flow and Heat Transfer in ITER Diagnostic First Wall

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khodak, A.; Loesser, G.; Zhai, Y.; Udintsev, V.; Klabacha, J.; Wang, W.; Johnson, D.; Feder, R.

    2015-07-24

    We performed numerical simulations of the ITER Diagnostic First Wall (DFW) using ANSYS workbench. During operation DFW will include solid main body as well as liquid coolant. Thus thermal and hydraulic analysis of the DFW was performed using conjugated heat transfer approach, in which heat transfer was resolved in both solid and liquid parts, and simultaneously fluid dynamics analysis was performed only in the liquid part. This approach includes interface between solid and liquid part of the systemAnalysis was performed using ANSYS CFX software. CFX software allows solution of heat transfer equations in solid and liquid part, and solution ofmore » the flow equations in the liquid part. Coolant flow in the DFW was assumed turbulent and was resolved using Reynolds averaged Navier-Stokes equations with Shear Stress Transport turbulence model. Meshing was performed using CFX method available within ANSYS. The data cloud for thermal loading consisting of volumetric heating and surface heating was imported into CFX Volumetric heating source was generated using Attila software. Surface heating was obtained using radiation heat transfer analysis. Our results allowed us to identify areas of excessive heating. Proposals for cooling channel relocation were made. Additional suggestions were made to improve hydraulic performance of the cooling system.« less

  10. FEMCAM Analysis of SULTAN Test Results for ITER Nb3SN Cable-conduit Conductors

    SciTech Connect (OSTI)

    Yuhu Zhai, Pierluigi Bruzzone, Ciro Calzolaio

    2013-03-19

    Performance degradation due to filament fracture of Nb3 Sn cable-in-conduit conductors (CICCs) is a critical issue in large-scale magnet designs such as ITER which is currently being constructed in the South of France. The critical current observed in most SULTAN TF CICC samples is significantly lower than expected and the voltage-current characteristic is seen to have a much broader transition from a single strand to the CICC. Moreover, most conductors exhibit the irreversible degradation due to filament fracture and strain relaxation under electromagnetic cyclic loading. With recent success in monitoring thermal strain distribution and its evolution under the electromagnetic cyclic loading from in situ measurement of critical temperature, we apply FEMCAM which includes strand filament breakage and local current sharing effects to SULTAN tested CICCs to study Nb3 Sn strain sensitivity and irreversible performance degradation. FEMCAM combines the thermal bending effect during cool down and the EM bending effect due to locally accumulating Lorentz force during magnet operation. It also includes strand filament fracture and related local current sharing for the calculation of cable n value. In this paper, we model continuous performance degradation under EM cyclic loading based on strain relaxation and the transition broadening upon cyclic loading to the extreme cases seen in SULTAN test data to better quantify conductor performance degradation.

  11. Integrated simulations of saturated neoclassical tearing modes in DIII-D, Joint European Torus, and ITER plasmas

    SciTech Connect (OSTI)

    Halpern, Federico D.; Bateman, Glenn; Kritz, Arnold H.

    2006-06-15

    A revised version of the ISLAND module [C. N. Nguyen et al., Phys. Plasmas 11, 3604 (2004)] is used in the BALDUR code [C. E. Singer et al., Comput. Phys. Commun. 49, 275 (1988)] to carry out integrated modeling simulations of DIII-D [J. Luxon, Nucl. Fusion 42, 614 (2002)], Joint European Torus (JET) [P. H. Rebut et al., Nucl. Fusion 25, 1011 (1985)], and ITER [R. Aymar et al., Plasma Phys. Control. Fusion 44, 519 (2002)] tokamak discharges in order to investigate the adverse effects of multiple saturated magnetic islands driven by neoclassical tearing modes (NTMs). Simulations are carried out with a predictive model for the temperature and density pedestal at the edge of the high confinement mode (H-mode) plasma and with core transport described using the Multi-Mode model. The ISLAND module, which is used to compute magnetic island widths, includes the effects of an arbitrary aspect ratio and plasma cross sectional shape, the effect of the neoclassical bootstrap current, and the effect of the distortion in the shape of each magnetic island caused by the radial variation of the perturbed magnetic field. Radial transport is enhanced across the width of each magnetic island within the BALDUR integrated modeling simulations in order to produce a self-consistent local flattening of the plasma profiles. It is found that the main consequence of the NTM magnetic islands is a decrease in the central plasma temperature and total energy. For the DIII-D and JET discharges, it is found that inclusion of the NTMs typically results in a decrease in total energy of the order of 15%. In simulations of ITER, it is found that the saturated magnetic island widths normalized by the plasma minor radius, for the lowest order individual tearing modes, are approximately 24% for the 2/1 mode and 12% for the 3/2 mode. As a result, the ratio of ITER fusion power to heating power (fusion Q) is reduced from Q=10.6 in simulations with no NTM islands to Q=2.6 in simulations with fully saturated

  12. Public Involvement and Communications Committee:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    purposes only 09.08.15 Excerpt from the HAB Process Manual January 2012 Public Involvement and Communications Committee: Develops Board Advice for the TPA agencies on the...

  13. Public Involvement Committee - Transcribed Flipcharts

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    September 3, 2014 Public Involvement Opportunities * Review of PI materials and agency websites, listservs (use of and purpose of notifications). * CD process - approach to PI...

  14. Design and Analysis of the ITER Vertical Stability Coils

    SciTech Connect (OSTI)

    Peter H. Titus, et. al.

    2012-09-06

    The ITER vertical stability (VS) coils have been developed through the preliminary design phase by Princeton Plasma Physics Laboratory (PPPL). Final design, prototyping and construction will be carried out by the Chinese Participant Team contributing lab, Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). The VS coils are a part of the in-vessel coil systems which include edge localized mode (ELM) coils as well as the VS coils. An overview of the ELM coils is provided in another paper at this conference. 15 The VS design employs four turns of stainless steel jacketed mineral insulated copper (SSMIC) conductors The mineral insulation is Magnesium Oxide (MgO). Joule and nuclear heat is removed by water flowing at 3 m/s through the hollow copper conductor. A key element in the design is that slightly elevated temperatures in the conductor and its support spine during operation impose compressive stresses that mitigate fatigue damage. Away from joints, and break-outs, conductor thermal stresses are low because of the axisymmetry of the winding (there are no corner bends as in the ELM coils).The 120 degree segment joint, and break-out or terminal regions are designed with similar but imperfect constraint compared with the ring coil portion of the VS. The support for the break-out region is made from a high strength copper alloy, CuCrZr. This is needed to conduct nuclear heat to the actively cooled conductor and to the vessel wall. The support "spine" for the ring coil portion of the VS is 316 stainless steel, held to the vessel with preloaded 718 bolts. Lorentz loads resulting from normal operating loads, disruption loads and loads from disruption currents in the support spine shared with vessel, are applied to the VS coil. The transmission of the Lorentz and thermal expansion loads from the "spine" to the vessel rails is via friction augmented with a restraining "lip" to ensure the coil frictional slip is minimal and acceptable. Stresses in the coil

  15. ITER Building Design (D230-B), Task No. 28. Final report

    SciTech Connect (OSTI)

    1995-12-01

    The International Thermonuclear Experimental Reactor (ITER) Project requires a set of buildings, each with its own distinct function, to support ITER`s mission. The Joint Central Team (JCT) has identified all the buildings in the set and has placed them in an efficient arrangement on the site. The JCT has developed a conceptual layout of each individual building. The buildings have been categorized into two main groups: (1) {open_quotes}Level 1 Buildings{close_quotes} which are on the construction schedule critical path and (2) {open_quotes}Level 2 Buildings{close_quotes} which, while important, are not on the critical path. The buildings are further categorized according to construction material, that is, {open_quotes}reinforced concrete{close_quotes} or {open_quotes}steel-frame on concrete slab{close_quotes}. This Report responds to the Project`s request to perform the initial structural steel design for all the {open_quotes}steel-frame on concrete slab{close_quotes} buildings. Of the twelve (12) {open_quotes}steel-frame on concrete slab{close_quotes} buildings, four (4) are Level 1 and eight (8) are Level 2 Buildings. This Report is a deliverable for the ITER Task Assignment entitled {open_quotes}ITER Buildings Design (D230-B){close_quotes}, also designated as Task No. 28. ITER U.S. Home Team Industrial Consortium members, Raytheon Engineers & Constructors (RE&C) and Stone & Webster Engineering Corporation (SWEC), teamed to perform Task 28. This task commenced in May 1995. It was performed in accordance with the design criteria specified by the ITER-JCT, San Diego Joint Work Site.

  16. Method and apparatus for iterative lysis and extraction of algae

    DOE Patents [OSTI]

    Chew, Geoffrey; Boggs, Tabitha; Dykes, Jr., H. Waite H.; Doherty, Stephen J.

    2015-12-01

    A method and system for processing algae involves the use of an ionic liquid-containing clarified cell lysate to lyse algae cells. The resulting crude cell lysate may be clarified and subsequently used to lyse algae cells. The process may be repeated a number of times before a clarified lysate is separated into lipid and aqueous phases for further processing and/or purification of desired products.

  17. TRANSP Tests Of TGLF and Predictions For ITER

    SciTech Connect (OSTI)

    Robert V Budny, et al

    2013-06-02

    Gyro kinetic simulations of turbulence capture some of the features observed in transport, fluctuations, and correlations measured in tokamak plasmas. These codes calculations are CPU intensive, and are not practical for incorporation in present time-dependant transport codes, so reduced models based on these gyro kinetic codes are being used. An example is the TGLF model [1] which is a quasilinear gyrofluid model calibrated to nonlinear results from the GYRO code [2]. Recently TGLF has been incorporated into TRANSP [3].

  18. Heating and current drive requirements towards steady state operation in ITER

    SciTech Connect (OSTI)

    Poli, F. M.; Kessel, C. E.; Gorelenkova, M.; Bonoli, P. T.; Batchelor, D. B.; Harvey, B.; Petrov, Y.

    2014-02-12

    Steady state scenarios envisaged for ITER aim at optimizing the bootstrap current, while maintaining sufficient confinement and stability to provide the necessary fusion yield. Non-inductive scenarios will need to operate with Internal Transport Barriers (ITBs) in order to reach adequate fusion gain at typical currents of 9 MA. However, the large pressure gradients associated with ITBs in regions of weak or negative magnetic shear can be conducive to ideal MHD instabilities, reducing the no-wall limit. The E × B flow shear from toroidal plasma rotation is expected to be low in ITER, with a major role in the ITB dynamics being played by magnetic geometry. Combinations of H/CD sources that maintain weakly reversed magnetic shear profiles throughout the discharge are the focus of this work. Time-dependent transport simulations indicate that, with a trade-off of the EC equatorial and upper launcher, the formation and sustainment of quasi-steady state ITBs could be demonstrated in ITER with the baseline heating configuration. However, with proper constraints from peeling-ballooning theory on the pedestal width and height, the fusion gain and the maximum non-inductive current are below the ITER target. Upgrades of the heating and current drive system in ITER, like the use of Lower Hybrid current drive, could overcome these limitations, sustaining higher non-inductive current and confinement, more expanded ITBs which are ideal MHD stable.

  19. ITER vacuum vessel fabrication plan and cost study (D 68) for the international thermonuclear experimental reactor

    SciTech Connect (OSTI)

    1995-01-01

    ITER Task No. 8, Vacuum Vessel Fabrication Plan and Cost Study (D68), was initiated to assess ITER vacuum vessel fabrication, assembly, and cost. The industrial team of Raytheon Engineers & Constructors and Chicago Bridge & Iron (Raytheon/CB&I) reviewed the current vessel basis and prepared a manufacturing plan, assembly plan, and cost estimate commensurate with the present design. The guidance for the Raytheon/CB&I assessment activities was prepared by the ITER Garching Work Site. This guidance provided in the form of work descriptions, sketches, drawings, and costing guidelines for each of the presently identified vacuum vessel Work Breakdown Structure (WBS) elements was compiled in ITER Garching Joint Work Site Memo (Draft No. 9 - G 15 MD 01 94-17-05 W 1). A copy of this document is provided as Appendix 1 to this report. Additional information and clarifications required for the Raytheon/CB&I assessments were coordinated through the US Home Team (USHT) and its technical representative. Design details considered essential to the Task 8 assessments but not available from the ITER Joint Central Team (JCT) were generated by Raytheon/CB&I and documented accordingly.

  20. An iterative method for the solution of nonlinear systems using the Faber polynomials for annular sectors

    SciTech Connect (OSTI)

    Myers, N.J.

    1994-12-31

    The author gives a hybrid method for the iterative solution of linear systems of equations Ax = b, where the matrix (A) is nonsingular, sparse and nonsymmetric. As in a method developed by Starke and Varga the method begins with a number of steps of the Arnoldi method to produce some information on the location of the spectrum of A. This method then switches to an iterative method based on the Faber polynomials for an annular sector placed around these eigenvalue estimates. The Faber polynomials for an annular sector are used because, firstly an annular sector can easily be placed around any eigenvalue estimates bounded away from zero, and secondly the Faber polynomials are known analytically for an annular sector. Finally the author gives three numerical examples, two of which allow comparison with Starke and Varga`s results. The third is an example of a matrix for which many iterative methods would fall, but this method converges.

  1. Numerical studies of the imaging properties of doubly focussing crystals and their application to ITER

    SciTech Connect (OSTI)

    Bitter, M.; Fraenkel, B.; Hill, K.W.; Hsuan, H.; von Goeler, S. )

    1995-01-01

    Line brightness calculations for the parameters at the International Thermonuclear Experimental Reactor (ITER) and results from recent experiments on the Tokamak Fusion Test Reactor (TFTR) indicate that time-resolved measurements of the central ion temperature and other central plasma parameters should be feasible on ITER with nonperturbing amounts of krypton. Since the measurements will have to be performed in the presence of high fluxes of 14-MeV neutrons from DT-fusion reactions, the size of windows, apertures and x-ray detectors must be as small as possible. Under these conditions, the use of doubly focussing crystals can significantly enhance the signal-to-noise ratio. This paper describes numerical studies of the focussing properties of spherically bent crystals and their application to ITER.

  2. Radiative Decays Involving Light Scalar Mesons

    SciTech Connect (OSTI)

    Deirdre Black; Masayasu Harada; Joseph Schechter

    2002-09-01

    We present a vector dominance model to describe radiative decays involving the light scalar mesons. Assuming that the light scalar mesons form a nonet this model gives relations among various decay amplitudes of the form S--> gamma gamma, V-->Sgamma and S--> Vgamma, where S and V denote scalar and vector mesons. By comparing with experimental radiative decay rates, including those recently measured for phi--> PP'gamma, we obtain various predictions. We discuss briefly ongoing extensions of the present work in an attempt to describe the radiative phi decay measurements in detail.

  3. Electromagnetic Analysis For The Design Of ITER Diagnostic Port Plugs During Plasma Disruptions

    SciTech Connect (OSTI)

    Zhai, Y

    2014-03-03

    ITER diagnostic port plugs perform many functions including structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to plasma. The design of diagnotic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate response of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs). Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration due to electrical contact among various EPP structural components are discussed.

  4. Beyond ITER: Neutral beams for a demonstration fusion reactor (DEMO) (invited)

    SciTech Connect (OSTI)

    McAdams, R.

    2014-02-15

    In the development of magnetically confined fusion as an economically sustainable power source, International Tokamak Experimental Reactor (ITER) is currently under construction. Beyond ITER is the demonstration fusion reactor (DEMO) programme in which the physics and engineering aspects of a future fusion power plant will be demonstrated. DEMO will produce net electrical power. The DEMO programme will be outlined and the role of neutral beams for heating and current drive will be described. In particular, the importance of the efficiency of neutral beam systems in terms of injected neutral beam power compared to wallplug power will be discussed. Options for improving this efficiency including advanced neutralisers and energy recovery are discussed.

  5. Electromagnetic Analysis of ITER Diagnostic Equatorial Port Plugs During Plasma Disruptions

    SciTech Connect (OSTI)

    Y. Zhai, R. Feder, A. Brooks, M. Ulrickson, C.S. Pitcher and G.D. Loesser

    2012-08-27

    ITER diagnostic port plugs perform many functionsincluding structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to the plasma. The design of diagnostic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate responses of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs), Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration due to electrical contact among various EPP structural components are discussed.

  6. Non-destructive qualification tests for ITER cryogenic axial insulating breaks

    SciTech Connect (OSTI)

    Kosek, Jacek; Lopez, Roberto; Tommasini, Davide; Rodriguez-Mateos, Felix

    2014-01-29

    In the ITER superconducting magnets the dielectric separation between the CICC (Cable-In-Conduit Conductors) and the helium supply pipes is made through the so-called insulating breaks (IB). These devices shall provide the required dielectric insulation at a 30 kV level under different types of stresses and constraints: thermal, mechanical, dielectric and ionizing radiations. As part of the R and D program, the ITER Organization launched contracts with industrial companies aimed at the qualification of the manufacturing techniques. After reviewing the main functional aspects, this paper describes and discusses the protocol established for non-destructive qualification tests of the prototypes.

  7. Rich Hawryluk recalls "exciting and challenging" years working on ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    | Princeton Plasma Physics Lab Rich Hawryluk recalls "exciting and challenging" years working on ITER By John Greenwald April 23, 2013 Tweet Widget Google Plus One Share on Facebook Gallery: What is it like to be at the center of ITER, the huge international fusion experiment that is under construction in Cadarache, France? "It's both exciting and challenging," said physicist Rich Hawryluk, who recently returned to PPPL after a two-year stint as deputy director-general

  8. Planning for U.S. Fusion Community Participation in the ITER Program

    SciTech Connect (OSTI)

    Baker, Charles; Berk, Herbert; Greenwald, Martin; Mauel, Michael E.; Najmabadi, Farrokh; Nevins, William M.; Stambaugh, Ronald; Synakowski, Edmund; Batchelor, Donald B.; Fonck, Raymond; Hawryluk, Richard J.; Meade, Dale M.; Neilson, George H.; Parker, Ronald; Strait, Ted

    2006-06-07

    A central step in the mission of the U.S. Fusion Energy Sciences program is the creation and study of a fusion-powered "star on earth", where the same energy source that drives the sun and other stars is reproduced and controlled for sustained periods in the laboratory. This “star” is formed by an ionized gas, or plasma, heated to fusion temperatures in a magnetic confinement device known as a tokamak, which is the most advanced magnetic fusion concept. The ITER tokamak is designed to be the premier scientific tool for exploring and testing expectations for plasma behavior in the fusion burning plasma regime, wherein the fusion process itself provides the dominant heat source to sustain the plasma temperature. It will provide the scientific basis and control tools needed to move toward the fusion energy goal. The ITER project confronts the grand challenge of creating and understanding a burning plasma for the first time. The distinguishing characteristic of a burning plasma is the tight coupling between the fusion heating, the resulting energetic particles, and the confinement and stability properties of the plasma. Achieving this strongly coupled burning state requires resolving complex physics issues and integrating challenging technologies. A clear and comprehensive scientific understanding of the burning plasma state is needed to confidently extrapolate plasma behavior and related technology beyond ITER to a fusion power plant. Developing this predictive understanding is the overarching goal of the U.S. Fusion Energy Sciences program. The burning plasma research program in the U.S. is being organized to maximize the scientific benefits of U.S. participation in the international ITER experiment. It is expected that much of the research pursued on ITER will be based on the scientific merit of proposed activities, and it will be necessary to maintain strong fusion research capabilities in the U.S. to successfully contribute to the success of ITER and optimize

  9. Objective assessment of image quality and dose reduction in CT iterative reconstruction

    SciTech Connect (OSTI)

    Vaishnav, J. Y. Jung, W. C.; Popescu, L. M.; Zeng, R.; Myers, K. J.

    2014-07-15

    Purpose: Iterative reconstruction (IR) algorithms have the potential to reduce radiation dose in CT diagnostic imaging. As these algorithms become available on the market, a standardizable method of quantifying the dose reduction that a particular IR method can achieve would be valuable. Such a method would assist manufacturers in making promotional claims about dose reduction, buyers in comparing different devices, physicists in independently validating the claims, and the United States Food and Drug Administration in regulating the labeling of CT devices. However, the nonlinear nature of commercially available IR algorithms poses challenges to objectively assessing image quality, a necessary step in establishing the amount of dose reduction that a given IR algorithm can achieve without compromising that image quality. This review paper seeks to consolidate information relevant to objectively assessing the quality of CT IR images, and thereby measuring the level of dose reduction that a given IR algorithm can achieve. Methods: The authors discuss task-based methods for assessing the quality of CT IR images and evaluating dose reduction. Results: The authors explain and review recent literature on signal detection and localization tasks in CT IR image quality assessment, the design of an appropriate phantom for these tasks, possible choices of observers (including human and model observers), and methods of evaluating observer performance. Conclusions: Standardizing the measurement of dose reduction is a problem of broad interest to the CT community and to public health. A necessary step in the process is the objective assessment of CT image quality, for which various task-based methods may be suitable. This paper attempts to consolidate recent literature that is relevant to the development and implementation of task-based methods for the assessment of CT IR image quality.

  10. DOE - NNSA/NFO -- EM Public Involvement

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Public Involvement NNSANFO Language Options U.S. DOENNSA - Nevada Field Office Click to subscribe to NNSS News Public Involvement Public Involvement Outreach Photo An integral ...

  11. Fast Acting Eddy Current Driven Valve for Massive Gas Injection on ITER

    SciTech Connect (OSTI)

    Lyttle, Mark S; Baylor, Larry R; Carmichael, Justin R; Combs, Stephen Kirk; Ericson, Milton Nance; Ezell, N Dianne Bull; Meitner, S. J.; Rasmussen, David A; Warmack, Robert J Bruce; Maruyama, So; Kiss, Gabor

    2015-01-01

    Tokamak plasma disruptions present a significant challenge to ITER as they can result in intense heat flux, large forces from halo and eddy currents, and potential first-wall damage from the generation of multi-MeV runaway electrons. Massive gas injection (MGI) of high Z material using fast acting valves is being explored on existing tokamaks and is planned for ITER as a method to evenly distribute the thermal load of the plasma to prevent melting, control the rate of the current decay to minimize mechanical loads, and to suppress the generation of runaway electrons. A fast acting valve and accompanying power supply have been designed and first test articles produced to meet the requirements for a disruption mitigation system on ITER. The test valve incorporates a flyer plate actuator similar to designs deployed on TEXTOR, ASDEX upgrade, and JET [1 3] of a size useful for ITER with special considerations to mitigate the high mechanical forces developed during actuation due to high background magnetic fields. The valve includes a tip design and all-metal valve stem sealing for compatibility with tritium and high neutron and gamma fluxes.

  12. Amesos2 and Belos: Direct and Iterative Solvers for Large Sparse Linear Systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bavier, Eric; Hoemmen, Mark; Rajamanickam, Sivasankaran; Thornquist, Heidi

    2012-01-01

    Solvers for large sparse linear systems come in two categories: direct and iterative. Amesos2, a package in the Trilinos software project, provides direct methods, and Belos, another Trilinos package, provides iterative methods. Amesos2 offers a common interface to many different sparse matrix factorization codes, and can handle any implementation of sparse matrices and vectors, via an easy-to-extend C++ traits interface. It can also factor matrices whose entries have arbitrary “Scalar” type, enabling extended-precision and mixed-precision algorithms. Belos includes many different iterative methods for solving large sparse linear systems and least-squares problems. Unlike competing iterative solver libraries, Belos completely decouples themore » algorithms from the implementations of the underlying linear algebra objects. This lets Belos exploit the latest hardware without changes to the code. Belos favors algorithms that solve higher-level problems, such as multiple simultaneous linear systems and sequences of related linear systems, faster than standard algorithms. The package also supports extended-precision and mixed-precision algorithms. Together, Amesos2 and Belos form a complete suite of sparse linear solvers.« less

  13. Requirements for US regulatory approval of the International Thermonuclear Experimental Reactor (ITER)

    SciTech Connect (OSTI)

    Petti, D.A.; Haire, J.C.

    1993-12-01

    The International Thermonuclear Experimental Reactor (ITER) is the first fusion machine that will have sufficient decay heat and activation product inventory to pose potential nuclear safety concerns. As a result, nuclear safety and environmental issues will be much more important in the approval process for the design, siting, construction, and operation of ITER in the United States than previous fusion devices, such as the Tokamak Fusion Test Reactor. The purpose of this report is (a) to provide an overview of the regulatory approval process for a Department of Energy (DOE) nuclear facility; (b) to present the dose limits used by DOE to protect workers, the public, and the environment from the risks of exposure to radiation and hazardous materials; (c) to discuss some key nuclear safety-related issues that must be addressed early in the Engineering Design Activities (EDA) to obtain regulatory approval; and (d) to provide general guidelines to the ITER Joint Central Team (JCT) concerning the development of a regulatory framework for the ITER project.

  14. Lorentz and CPT tests involving antiprotons

    SciTech Connect (OSTI)

    Lehnert, Ralf

    2005-10-19

    Perhaps the largest gap in our understanding of nature at the smallest scales is a consistent quantum theory underlying the Standard Model and General Relativity. Substantial theoretical research has been performed in this context, but observational efforts are hampered by the expected Planck suppression of deviations from conventional physics. However, a variety of candidate models predict minute violations of both Lorentz and CPT invariance. Such effects open a promising avenue for experimental research in this field because these symmetries are amenable to Planck-precision tests.The low-energy signatures of Lorentz and CPT breaking are described by an effective field theory called the Standard-Model Extension (SME). In addition to the body of established physics (i.e., the Standard Model and General Relativity), this framework incorporates all Lorentz- and CPT-violating corrections compatible with key principles of physics. To date, the SME has provided the basis for the analysis of numerous tests of Lorentz and CPT symmetry involving protons, neutrons, electrons, muons, and photons. Discovery potential exists in neutrino physics.A particularly promising class of Planck-scale tests involve matter-antimatter comparisons at low temperatures. SME predictions for transition frequencies in such systems include both matter-antimatter differences and sidereal variations. For example, in hydrogen-antihydrogen spectroscopy, leading-order effects in a 1S-2S transition as well as in a 1S Zeeman transition could exist that can be employed to obtain clean constraints. Similarly, tight bounds can be obtained from Penning-trap experiments involving antiprotons.

  15. U.S. ITER | Princeton Plasma Physics Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Policy Analysts This page features the most requested EIA reports and features for policy analysts. If you can't find what you're looking for, please contact the EIA Information Center. Featured Links Responses to Congressional and other requests Congressional testimony Analysis papers from Annual Energy Outlook Financial data and analysis Environmental data and analysis National Energy Modeling System (NEMS) documentation Energy in Brief Maps Featured Reports Annual Energy Outlook International

  16. Twin-Screw Extruder Development for the ITER Pellet Injection System

    SciTech Connect (OSTI)

    Meitner, Steven J; Baylor, Larry R; Combs, Stephen Kirk; Fehling, Dan T; McGill, James M; Rasmussen, David A; Leachman, J. W.

    2009-01-01

    The ITER pellet injection system is comprised of devices to form and accelerate pellets, and will be connected to inner wall guide tubes for fueling, and outer wall guide tubes for ELM pacing. An extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with a gas gun into the plasma. The ITER pellet injection system is required to provide a plasma fueling rate of 120 Pa-m3/s (900 mbar-L/s) and durations of up to 3000 s. The fueling pellets will be injected at a rate up to 10 Hz and pellets used to trigger ELMs will be injected at higher rates up to 20 Hz. A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. A one-fifth ITER scale prototype has been built and has demonstrated the production of a continuous solid deuterium extrusion. The 27 mm diameter, intermeshed, counter-rotating extruder screws are rotated at a rate up to ?5 rpm. Deuterium gas is pre-cooled and liquefied and solidified in separate extruder barrels. The precooler consists of a deuterium gas filled copper coil suspended in a separate stainless steel vessel containing liquid nitrogen. The liquefier is comprised of a copper barrel connected to a Cryomech AL330 cryocooler, which has a machined helical groove surrounded by a copper jacket, through which the pre-cooled deuterium condenses. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at ?15 K) before it is forced through the extruder die. The die forms the extrusion to a 3 mm x 4 mm rectangular cross section. Design improvements have been made to improve the pre-cooler and liquefier heat exchangers, to limit the loss of extrusion through gaps in the screws. This paper will describe the design improvements for the next iteration of the extruder prototype.

  17. Iterative electromagnetic Born inversion applied to earth conductivity imaging

    SciTech Connect (OSTI)

    Alumbaugh, D.L.

    1993-08-01

    This thesis investigates the use of a fast imaging technique to deduce the spatial conductivity distribution in the earth from low frequency (< 1 MHz), cross well electromagnetic (EM) measurements. The theory embodied in this work is the extension of previous strategies and is based on the Born series approximation to solve both the forward and inverse problem. Nonlinear integral equations are employed to derive the series expansion which accounts for the scattered magnetic fields that are generated by inhomogeneities embedded in either a homogenous or a layered earth. A sinusoidally oscillating, vertically oriented magnetic dipole is employed as a source, and it is assumed that the scattering bodies are azimuthally symmetric about the source dipole axis. The use of this model geometry reduces the 3-D vector problem to a more manageable 2-D scalar form. The validity of the cross well EM method is tested by applying the imaging scheme to two sets of field data. Images of the data collected at the Devine, Texas test site show excellent correlation with the well logs. Unfortunately there is a drift error present in the data that limits the accuracy of the results. A more complete set of data collected at the Richmond field station in Richmond, California demonstrates that cross well EM can be successfully employed to monitor the position of an injected mass of salt water. Both the data and the resulting images clearly indicate the plume migrates toward the north-northwest. The plausibility of these conclusions is verified by applying the imaging code to synthetic data generated by a 3-D sheet model.

  18. HOW YOU CAN BE INVOLVED

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    HOW YOU CAN BE INVOLVED www.youtube.com/hanfordsite www.twitter.com/hanfordsite www.facebook.com/hanfordsite The Hanford Site sits on 586-square-miles of shrub-steppe desert in southeastern Washington state. The site was created in 1943 as part of the Manhattan Project to produce plutonium for nuclear weapons. Between 1943 and 1963, nine nuclear reactors were built along the banks of the Columbia River. By 1988, all nine reactors were shut down. The weapons material production mission ended in

  19. Reducing the effects of acoustic heterogeneity with an iterative reconstruction method from experimental data in microwave induced thermoacoustic tomography

    SciTech Connect (OSTI)

    Wang, Jinguo; Zhao, Zhiqin Song, Jian; Chen, Guoping; Nie, Zaiping; Liu, Qing-Huo

    2015-05-15

    Purpose: An iterative reconstruction method has been previously reported by the authors of this paper. However, the iterative reconstruction method was demonstrated by solely using the numerical simulations. It is essential to apply the iterative reconstruction method to practice conditions. The objective of this work is to validate the capability of the iterative reconstruction method for reducing the effects of acoustic heterogeneity with the experimental data in microwave induced thermoacoustic tomography. Methods: Most existing reconstruction methods need to combine the ultrasonic measurement technology to quantitatively measure the velocity distribution of heterogeneity, which increases the system complexity. Different to existing reconstruction methods, the iterative reconstruction method combines time reversal mirror technique, fast marching method, and simultaneous algebraic reconstruction technique to iteratively estimate the velocity distribution of heterogeneous tissue by solely using the measured data. Then, the estimated velocity distribution is used subsequently to reconstruct the highly accurate image of microwave absorption distribution. Experiments that a target placed in an acoustic heterogeneous environment are performed to validate the iterative reconstruction method. Results: By using the estimated velocity distribution, the target in an acoustic heterogeneous environment can be reconstructed with better shape and higher image contrast than targets that are reconstructed with a homogeneous velocity distribution. Conclusions: The distortions caused by the acoustic heterogeneity can be efficiently corrected by utilizing the velocity distribution estimated by the iterative reconstruction method. The advantage of the iterative reconstruction method over the existing correction methods is that it is successful in improving the quality of the image of microwave absorption distribution without increasing the system complexity.

  20. Experimental neutronics tests for a neutron activation system for the European ITER TBM

    SciTech Connect (OSTI)

    Klix, A.; Fischer, U.; Gehre, D.; Kleizer, G.; Raj, P.; Rovni, I.; Ruecker, Tom

    2014-08-21

    We are investigating methods for neutron flux measurement in the ITER TBM. In particular we have tested sets of activation materials leading to induced gamma activities with short half-lives of the order of tens of seconds up to minutes and standard activation materials. Packages of activation foils have been irradiated with the intense neutron generator of Technical University of Dresden in a pure DT neutron field as well as in a neutronics mock-up of the European ITER HCLL TBM. An important aim was to check whether the gamma activity induced in the activation foils in these packages could be measured simultaneously. It was indeed possible to identify gamma lines of interest in gamma-ray measurements immediately after extraction from the irradiation.

  1. The ITER pre-compression rings – A first in cryogenic composite technology

    SciTech Connect (OSTI)

    Rajainmaki, Hannu; Fanthome, John; Losasso, Marcello; Rodriguez, Jesus; Evans, David; Diaz, Victor

    2014-01-27

    The ITER Pre-Compression Rings represent one of the heaviest composite structures ever manufactured as a single piece and the largest - the outer diameter will be above 5.5 meters - intended for use in a cryogenic environment. With a cross section of 337 mm × 288 mm, each item will weigh more than 3,000 kg. A development program, based on filament wound and dry wound S2 glass unidirectional fibers, the latter processed by VARTM, was completed on one fifth scale rings, and these materials and techniques were shown to be satisfactory. The paper describes how a technology applied to build up primary structures of European launchers is being accommodated to produce the ITER Pre-Compression Rings, fulfilling its extremely challenging requirements. In addition, we will describe how the structural analysis is correlated with the test results of scaled down rings, as well as how the pre-compression rings’ manufacturing process will be qualified.

  2. Radiation dose reduction in medical x-ray CT via Fourier-based iterative reconstruction

    SciTech Connect (OSTI)

    Fahimian, Benjamin P.; Zhao Yunzhe; Huang Zhifeng; Fung, Russell; Zhu Chun; Miao Jianwei; Mao Yu; Khatonabadi, Maryam; DeMarco, John J.; McNitt-Gray, Michael F.; Osher, Stanley J.

    2013-03-15

    Purpose: A Fourier-based iterative reconstruction technique, termed Equally Sloped Tomography (EST), is developed in conjunction with advanced mathematical regularization to investigate radiation dose reduction in x-ray CT. The method is experimentally implemented on fan-beam CT and evaluated as a function of imaging dose on a series of image quality phantoms and anonymous pediatric patient data sets. Numerical simulation experiments are also performed to explore the extension of EST to helical cone-beam geometry. Methods: EST is a Fourier based iterative algorithm, which iterates back and forth between real and Fourier space utilizing the algebraically exact pseudopolar fast Fourier transform (PPFFT). In each iteration, physical constraints and mathematical regularization are applied in real space, while the measured data are enforced in Fourier space. The algorithm is automatically terminated when a proposed termination criterion is met. Experimentally, fan-beam projections were acquired by the Siemens z-flying focal spot technology, and subsequently interleaved and rebinned to a pseudopolar grid. Image quality phantoms were scanned at systematically varied mAs settings, reconstructed by EST and conventional reconstruction methods such as filtered back projection (FBP), and quantified using metrics including resolution, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs). Pediatric data sets were reconstructed at their original acquisition settings and additionally simulated to lower dose settings for comparison and evaluation of the potential for radiation dose reduction. Numerical experiments were conducted to quantify EST and other iterative methods in terms of image quality and computation time. The extension of EST to helical cone-beam CT was implemented by using the advanced single-slice rebinning (ASSR) method. Results: Based on the phantom and pediatric patient fan-beam CT data, it is demonstrated that EST reconstructions with the lowest

  3. Review of the International Thermonuclear Experimental Reactor (ITER) detailed design report

    SciTech Connect (OSTI)

    1997-04-18

    Dr. Martha Krebs, Director, Office of Energy Research at the US Department of Energy (DOE), wrote to the Fusion Energy Sciences Advisory Committee (FESAC), in letters dated September 23 and November 6, 1996, requesting that FESAC review the International Thermonuclear Experimental Reactor (ITER) Detailed Design Report (DDR) and provide its view of the adequacy of the DDR as part of the basis for the United States decision to enter negotiations with the other interested Parties regarding the terms and conditions for an agreement for the construction, operations, exploitation and decommissioning of ITER. The letter from Dr. Krebs, referred to as the Charge Letter, provided context for the review and a set of questions of specific interest.

  4. Vacuum Bellows, Vacuum Piping, Cryogenic Break, and Copper Joint Failure Rate Estimates for ITER Design Use

    SciTech Connect (OSTI)

    L. C. Cadwallader

    2010-06-01

    The ITER international project design teams are working to produce an engineering design in preparation for construction of the International Thermonuclear Experimental Reactor (ITER) tokamak. During the course of this work, questions have arisen in regard to safety barriers and equipment reliability as important facets of system design. The vacuum system designers have asked several questions about the reliability of vacuum bellows and vacuum piping. The vessel design team has asked about the reliability of electrical breaks and copper-copper joints used in cryogenic piping. Research into operating experiences of similar equipment has been performed to determine representative failure rates for these components. The following chapters give the research results and the findings for vacuum system bellows, power plant stainless steel piping (amended to represent vacuum system piping), cryogenic system electrical insulating breaks, and copper joints.

  5. Design and Overview of 100 kV Bushing for the DNB Injector of ITER

    SciTech Connect (OSTI)

    Shah, Sejal; Bandyopadhyay, M.; Rotti, C.; Singh, M. J.; Roopesh, G.; Chakraborty, A. K. [ITER-India, Institute for Plasma Research, Gandhinagar-382025, Gujarat (India); Rajesh, S. [ITER-India, Institute for Plasma Research, Gandhinagar-382025, Gujarat (India); Microelectronics and Materials Physics Labs, P.O.Box 4500, FIN-90014 University of Oulu (Finland); Nishad, S.; Srusti, B. [DesignTech Systems Ltd, Banjara Hills, Hyderabad, Andhra Pradesh-500034 (India); Schunke, B.; Hemsworth, R.; Chareyre, J.; Svensson, L. [ITER Organisation, Route de Vinon, CS 90 046, 13067 St. Paul lez Durance Cedex (France)

    2011-09-26

    The 100 kV bushing is one of the most important and technologically challenging Safety Important Class (SIC) components of the Diagnostic Neutral Beam (DNB) injector of ITER. It forms interface between gas insulated electrical transmission line and torus primary vacuum and acts as a vacuum feedthrough of ITER. Design optimization has been carried out to meet the electric and structural requirements based on its classification. Unlike HNB bushing, single stage bushing is designed to provide 100 kV isolation. Finite Element Analysis (FEA) based optimization has been carried out for electrostatic and structural analysis. Manufacturing assembly sequence is studied and presented in this paper. However validation of the same is foreseen from manufacturer.

  6. Assessment of database for interaction of tritium with ITER plasma facing materials

    SciTech Connect (OSTI)

    Dolan, T.J.; Anderl, R.A.

    1994-09-01

    The present work surveys recent literature on hydrogen isotope interactions with Be, SS and Inconels, Cu, C, and V, and alloys of Cu and V. The goals are (1) to provide input to the International Thermonuclear Experimental Reactor (ITER) team to help with tritium source term estimates for the Early Safety and Environmental Characterization Study and (2) to provide guidance for planning additional research that will be needed to fill gaps in the present materials database. Properties of diffusivity, solubility, permeability, chemical reactions, Soret effect, recombination coefficient, surface effects, trapping, porosity, layered structures, interfaces, and oxides are considered. Various materials data are tabulated, and a matrix display shows an assessment of the quality of the data available for each main property of each material. Recommendations are made for interim values of diffusivity and solubility to be used, pending further discussion by the ITER community.

  7. In-Vessel Coil Material Failure Rate Estimates for ITER Design Use

    SciTech Connect (OSTI)

    L. C. Cadwallader

    2013-01-01

    The ITER international project design teams are working to produce an engineering design for construction of this large tokamak fusion experiment. One of the design issues is ensuring proper control of the fusion plasma. In-vessel magnet coils may be needed for plasma control, especially the control of edge localized modes (ELMs) and plasma vertical stabilization (VS). These coils will be lifetime components that reside inside the ITER vacuum vessel behind the blanket modules. As such, their reliability is an important design issue since access will be time consuming if any type of repair were necessary. The following chapters give the research results and estimates of failure rates for the coil conductor and jacket materials to be used for the in-vessel coils. Copper and CuCrZr conductors, and stainless steel and Inconel jackets are examined.

  8. US ITER (International Thermonuclear Experimental Reactor) shield and blanket design activities

    SciTech Connect (OSTI)

    Baker, C.C.

    1988-08-01

    This paper summarizes nuclear-related work in support of the US effort for the International Thermonuclear Experimental Reactor (ITER) Study. Primary tasks carried out during the past year include design improvements of the inboard shield developed for the TIBER concept, scoping studies of a variety of tritium breeding blanket options, development of necessary design guidelines and evaluation criteria for the blanket options, further safety considerations related to nuclear components, and issues regarding structural materials for an ITER device. The blanket concepts considered are the aqueous/Li salt solution, a water-cooled, solid breeder blanket, a helium-cooled, solid-breeder blanket, a blanket cooled by helium containing lithium-bearing particulates, and a blanket concept based on breeding tritium from He/sup 3/. 1 ref., 2 tabs.

  9. Application of ECH to the study of transport in ITER baseline scenario-like discharges in DIII-D

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pinsker, R. I.; Austin, M. E.; Ernst, D. R.; Garofalo, A. M.; Grierson, B. A.; Hosea, J. C.; Luce, T. C.; Marinoni, A.; McKee, G. R.; Perkins, R. J.; et al

    2015-03-12

    Recent DIII-D experiments in the ITER Baseline Scenario (IBS) have shown strong increases in fluctuations and correlated reduction of confinement associated with entering the electron-heating-dominated regime with strong electron cyclotron heating (ECH). The addition of 3.2 MW of 110 GHz EC power deposited at ρ~0.42 to IBS discharges with ~3 MW of neutral beam injection causes large increases in low-k and medium-k turbulent density fluctuations observed with Doppler backscatter (DBS), beam emission spectroscopy (BES) and phase-contrast imaging (PCI) diagnostics, correlated with decreases in the energy, particle, and momentum confinement times. Power balance calculations show the electron heat diffusivity χe more » increases significantly in the mid-radius region 0.4<ρ<0.8, which is roughly the same region where the DBS and BES diagnostics show the increases in turbulent density fluctuations. Confinement of angular momentum is also reduced during ECH. Studies with the TGYRO transport solver show that the model of turbulent transport embodied in the TGLF code quantitatively reproduces the measured transport in both the neutral beam (NB)-only and in the NB plus EC cases. A simple model of the decrease in toroidal rotation with EC power is set forth, which exhibits a bifurcation in the rotational state of the discharge.« less

  10. High-performance finite-difference time-domain simulations of C-Mod and ITER RF antennas

    SciTech Connect (OSTI)

    Jenkins, Thomas G. Smithe, David N.

    2015-12-10

    Finite-difference time-domain methods have, in recent years, developed powerful capabilities for modeling realistic ICRF behavior in fusion plasmas [1, 2, 3, 4]. When coupled with the power of modern high-performance computing platforms, such techniques allow the behavior of antenna near and far fields, and the flow of RF power, to be studied in realistic experimental scenarios at previously inaccessible levels of resolution. In this talk, we present results and 3D animations from high-performance FDTD simulations on the Titan Cray XK7 supercomputer, modeling both Alcator C-Mod’s field-aligned ICRF antenna and the ITER antenna module. Much of this work focuses on scans over edge density, and tailored edge density profiles, to study dispersion and the physics of slow wave excitation in the immediate vicinity of the antenna hardware and SOL. An understanding of the role of the lower-hybrid resonance in low-density scenarios is emerging, and possible implications of this for the NSTX launcher and power balance are also discussed. In addition, we discuss ongoing work centered on using these simulations to estimate sputtering and impurity production, as driven by the self-consistent sheath potentials at antenna surfaces.

  11. Application of ECH to the study of transport in ITER baseline scenario-like discharges in DIII-D

    SciTech Connect (OSTI)

    Pinsker, R. I.; Austin, M. E.; Ernst, D. R.; Garofalo, A. M.; Grierson, B. A.; Hosea, J. C.; Luce, T. C.; Marinoni, A.; McKee, G. R.; Perkins, R. J.; Petty, C. C.; Porkolab, M.; Rost, J. C.; Schmitz, L.; Solomon, W. M.; Taylor, G.; Turco, F.

    2015-03-12

    Recent DIII-D experiments in the ITER Baseline Scenario (IBS) have shown strong increases in fluctuations and correlated reduction of confinement associated with entering the electron-heating-dominated regime with strong electron cyclotron heating (ECH). The addition of 3.2 MW of 110 GHz EC power deposited at ρ~0.42 to IBS discharges with ~3 MW of neutral beam injection causes large increases in low-k and medium-k turbulent density fluctuations observed with Doppler backscatter (DBS), beam emission spectroscopy (BES) and phase-contrast imaging (PCI) diagnostics, correlated with decreases in the energy, particle, and momentum confinement times. Power balance calculations show the electron heat diffusivity χe increases significantly in the mid-radius region 0.4<ρ<0.8, which is roughly the same region where the DBS and BES diagnostics show the increases in turbulent density fluctuations. Confinement of angular momentum is also reduced during ECH. Studies with the TGYRO transport solver show that the model of turbulent transport embodied in the TGLF code quantitatively reproduces the measured transport in both the neutral beam (NB)-only and in the NB plus EC cases. A simple model of the decrease in toroidal rotation with EC power is set forth, which exhibits a bifurcation in the rotational state of the discharge.

  12. Public Involvement and Communications Committee Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8, 2012 FINAL MEETING SUMMARY HANFORD ADVISORY BOARD PUBLIC INVOLVEMENT & COMMUNICATIONS COMMITTEE MEETING February 8, 2012 Richland, WA Topics in this Meeting Summary Welcome and Introductions .......................................................................................................................... 1 Update on Timely Public Involvement Topics ............................................................................................. 1 Public Involvement for Technical

  13. Preliminary Neutronics Analysis of the ITER Toroidal Interferometer and Polarimeter Diagnostic Corner Cube Retroreflectors

    SciTech Connect (OSTI)

    Tresemer, K. R.

    2015-07-01

    ITER is an international project under construction in France that will demonstrate nuclear fusion at a power plant-relevant scale. The Toroidal Interferometer and Polarimeter (TIP) Diagnostic will be used to measure the plasma electron line density along 5 laser-beam chords. This line-averaged density measurement will be input to the ITER feedback-control system. The TIP is considered the primary diagnostic for these measurements, which are needed for basic ITER machine control. Therefore, system reliability & accuracy is a critical element in TIP’s design. There are two major challenges to the reliability of the TIP system. First is the survivability and performance of in-vessel optics and second is maintaining optical alignment over long optical paths and large vessel movements. Both of these issues greatly depend on minimizing the overall distortion due to neutron & gamma heating of the Corner Cube Retroreflectors (CCRs). These are small optical mirrors embedded in five first wall locations around the vacuum vessel, corresponding to certain plasma tangency radii. During the development of the design and location of these CCRs, several iterations of neutronics analyses were performed to determine and minimize the total distortion due to nuclear heating of the CCRs. The CCR corresponding to TIP Channel 2 was chosen for analysis as a good middle-road case, being an average distance from the plasma (of the five channels) and having moderate neutron shielding from its blanket shield housing. Results show that Channel 2 meets the requirements of the TIP Diagnostic, but barely. These results suggest other CCRs might be at risk of exceeding thermal deformation due to nuclear heating.

  14. Parallel iterative procedures for approximate solutions of wave propagation by finite element and finite difference methods

    SciTech Connect (OSTI)

    Kim, S.

    1994-12-31

    Parallel iterative procedures based on domain decomposition techniques are defined and analyzed for the numerical solution of wave propagation by finite element and finite difference methods. For finite element methods, in a Lagrangian framework, an efficient way for choosing the algorithm parameter as well as the algorithm convergence are indicated. Some heuristic arguments for finding the algorithm parameter for finite difference schemes are addressed. Numerical results are presented to indicate the effectiveness of the methods.

  15. Effects of coupling and asymmetries on load resilience of IC ITER-like structures

    SciTech Connect (OSTI)

    Bosia, G.; Bremond, S.; Colas, L.

    2005-09-26

    ITER-like structures feature an intrinsic resilience to load variations, which is related to the symmetry of the currents in the two branches of the structure. It has been suggested that the effects of coupling between the array elements would significantly impair the load resilience of the structure. In this paper the effect of inter strap coupling and of however induced electrical array asymmetries on the structure load resilience are quantitatively examined.

  16. PPPL and ITER: Lab teams support the world's largest fusion experiment

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with leading-edge ideas and design | Princeton Plasma Physics Lab and ITER: Lab teams support the world's largest fusion experiment with leading-edge ideas and design By John Greenwald May 7, 2013 Tweet Widget Google Plus One Share on Facebook PPPL scientists, engineers, technicians and other specialists contribute to the international project. (Photo by Elle Starkman/ PPPL Office of Communications) PPPL scientists, engineers, technicians and other specialists contribute to the international

  17. Absolutely and uniformly convergent iterative approach to inverse scattering with an infinite radius of convergence

    DOE Patents [OSTI]

    Kouri, Donald J.; Vijay, Amrendra; Zhang, Haiyan; Zhang, Jingfeng; Hoffman, David K.

    2007-05-01

    A method and system for solving the inverse acoustic scattering problem using an iterative approach with consideration of half-off-shell transition matrix elements (near-field) information, where the Volterra inverse series correctly predicts the first two moments of the interaction, while the Fredholm inverse series is correct only for the first moment and that the Volterra approach provides a method for exactly obtaining interactions which can be written as a sum of delta functions.

  18. Theory of runaway electrons in ITER: Equations, important parameters, and implications for mitigation

    SciTech Connect (OSTI)

    Boozer, Allen H.

    2015-03-15

    The plasma current in ITER cannot be allowed to transfer from thermal to relativistic electron carriers. The potential for damage is too great. Before the final design is chosen for the mitigation system to prevent such a transfer, it is important that the parameters that control the physics be understood. Equations that determine these parameters and their characteristic values are derived. The mitigation benefits of the injection of impurities with the highest possible atomic number Z and the slowing plasma cooling during halo current mitigation to ≳40 ms in ITER are discussed. The highest possible Z increases the poloidal flux consumption required for each e-fold in the number of relativistic electrons and reduces the number of high energy seed electrons from which exponentiation builds. Slow cooling of the plasma during halo current mitigation also reduces the electron seed. Existing experiments could test physics elements required for mitigation but cannot carry out an integrated demonstration. ITER itself cannot carry out an integrated demonstration without excessive danger of damage unless the probability of successful mitigation is extremely high. The probability of success depends on the reliability of the theory. Equations required for a reliable Monte Carlo simulation are derived.

  19. Uncertainty assessment and analysis of ITER in-VV tritium inventory determination

    SciTech Connect (OSTI)

    Cristescu, I. R.; Cristescu, I.; Glugla, M.; Murdoch, D.; Ciattaglia, S.

    2008-07-15

    Tracking of tritium inventories on ITER will be essential to ensure that the safety limits established for the mobilizable tritium inventory in the vacuum vessel are not violated. Tritium will be delivered to the ITER site from outside suppliers. Staring with the tritium imports the value of tritium inventory at ITER site will be known with a certain error that will propagate in time. During plasma operation, shot by shot measurements of the tritium delivered to the Torus and recovered will allow the amount of tritium trapped in the Torus to be computed at the end of the day. A case study for different measuring techniques and several measuring points for the tritium recovered from Torus have been done. An alternative method is to measure overnight the variation in the inventory of the storage and delivery system and the associated error when this method will be employed are presented. In order to reduce the errors on the tritium trapped in-vessel, at certain time intervals a method of global tritium inventory will be performed. The method envisages the transfer of all the mobilizable tritium from the plant and measurement of this inventory in the self-assay beds from the storage and delivery system. Evaluation of the most important sources of error for the tritium trapped in-vessel and means of minimization are eventually presented. (authors)

  20. Engineering aspects of design and integration of ECE diagnostic in ITER

    SciTech Connect (OSTI)

    Udintsev, V. S.; Taylor, G.; Pandya, H. K.B.; Austin, M. E.; Casal, N.; Catalin, R.; Clough, M.; Cuquel, B.; Dapena, M.; Drevon, J. -M.; Feder, R.; Friconneau, J. P.; Giacomin, T.; Guirao, J.; Henderson, M. A.; Hughes, S.; Iglesias, S.; Johnson, D.; Kumar, Siddhart; Kumar, Vina; Levesy, B.; Loesser, D.; Messineo, M.; Penot, C.; Portalès, M.; Oosterbeek, J. W.; Sirinelli, A; Vacas, C.; Vayakis, G.; Walsh, M. J.; Kubo, S.

    2015-03-12

    ITER ECE diagnostic [1] needs not only to meet measurement requirements, but also to withstand various loads, such as electromagnetic, mechanical, neutronic and thermal, and to be protected from stray ECH radiation at 170 GHz and other millimeter wave emission, like Collective Thomson scattering which is planned to operate at 60 GHz. Same or similar loads will be applied to other millimetre-wave diagnostics [2], located both in-vessel and in-port plugs. These loads must be taken into account throughout the design phases of the ECE and other microwave diagnostics to ensure their structural integrity and maintainability. The integration of microwave diagnostics with other ITER systems is another challenging activity which is currently ongoing through port integration and in-vessel integration work. Port Integration has to address the maintenance and the safety aspects of diagnostics, too. Engineering solutions which are being developed to support and to operate ITER ECE diagnostic, whilst complying with safety and maintenance requirements, are discussed in this paper.

  1. Engineering aspects of design and integration of ECE diagnostic in ITER

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Udintsev, V. S.; Taylor, G.; Pandya, H. K.B.; Austin, M. E.; Casal, N.; Catalin, R.; Clough, M.; Cuquel, B.; Dapena, M.; Drevon, J. -M.; et al

    2015-03-12

    ITER ECE diagnostic [1] needs not only to meet measurement requirements, but also to withstand various loads, such as electromagnetic, mechanical, neutronic and thermal, and to be protected from stray ECH radiation at 170 GHz and other millimeter wave emission, like Collective Thomson scattering which is planned to operate at 60 GHz. Same or similar loads will be applied to other millimetre-wave diagnostics [2], located both in-vessel and in-port plugs. These loads must be taken into account throughout the design phases of the ECE and other microwave diagnostics to ensure their structural integrity and maintainability. The integration of microwave diagnosticsmore » with other ITER systems is another challenging activity which is currently ongoing through port integration and in-vessel integration work. Port Integration has to address the maintenance and the safety aspects of diagnostics, too. Engineering solutions which are being developed to support and to operate ITER ECE diagnostic, whilst complying with safety and maintenance requirements, are discussed in this paper.« less

  2. DECONTAMINATION DRESSDOWN AT A TRANSPORTATION ACCIDENT INVOLVING...

    Office of Environmental Management (EM)

    Video User' s Guide DECONTAMINATION DRESSDOWN AT A TRANSPORTATION ACCIDENT INVOLVING ... related to emergency response to a transportation accident involving radioactive material. ...

  3. Community Involvement | Y-12 National Security Complex

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Involvement Community Involvement Y-12 is committed to keeping the community informed in areas of operations, environmental concerns, safety and emergency preparedness. To...

  4. Report of a technical evaluation panel on the use of beryllium for ITER plasma facing material and blanket breeder material

    SciTech Connect (OSTI)

    Ulrickson, M.A.; Manly, W.D.; Dombrowski, D.E.

    1995-08-01

    Beryllium because of its low atomic number and high thermal conductivity, is a candidate for both ITER first wall and divertor surfaces. This study addresses the following: why beryllium; design requirements for the ITER divertor; beryllium supply and unirradiated physical/mechanical property database; effects of irradiation on beryllium properties; tritium issues; beryllium health and safety; beryllium-coolant interactions and safety; thermal and mechanical tests; plasma erosion of beryllium; recommended beryllium grades for ITER plasma facing components; proposed manufacturing methods to produce beryllium parts for ITER; emerging beryllium materials; proposed inspection and maintenance techniques for beryllium components and coatings; time table and costs; and the importance of integrating materials and manufacturing personnel with designers.

  5. US ITER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    exposure at the Commerce Park site. Individuals are not required to wear the blue dosimeter badges at this site. 2.11 Worksite Warning Signs and Labels The typical signs you...

  6. Analysis of the phase control of the ITER ICRH antenna array. Influence on the load resilience and radiated power spectrum

    SciTech Connect (OSTI)

    Messiaen, A. Ongena, J.; Vervier, M.; Swain, D.

    2015-12-10

    The paper analyses how the phasing of the ITER ICRH 24 strap array evolves from the power sources up to the strap currents of the antenna. The study of the phasing control and coherence through the feeding circuits with prematching and automatic matching and decoupling network is made by modeling starting from the TOPICA matrix of the antenna array for a low coupling plasma profile and for current drive phasing (worst case for mutual coupling effects). The main results of the analysis are: (i) the strap current amplitude is well controlled by the antinode V{sub max} amplitude of the feeding lines, (ii) the best toroidal phasing control is done by the adjustment of the mean phase of V{sub max} of each poloidal straps column, (iii) with well adjusted system the largest strap current phasing error is ±20°, (iv) the effect on load resilience remains well below the maximum affordable VSWR of the generators, (v) the effect on the radiated power spectrum versus k{sub //} computed by means of the coupling code ANTITER II remains small for the considered cases.

  7. EMERGENCY RESPONSE TO A TRANSPORTATION ACCIDENT INVOLVING RADIOACTIVE...

    Office of Environmental Management (EM)

    ransportation ransportation ransportation ransportation Accident Involving Radioactive Material Accident Involving Radioactive Material Accident Involving Radioactive ...

  8. Conceptual design of the tangentially viewing combined interferometer-polarimeter for ITER density measurements

    SciTech Connect (OSTI)

    Van Zeeland, M. A.; Boivin, R. L.; Carlstrom, T. N.; Chavez, J. A.; O'Neill, R. C.; Brower, D. L.; Ding, W. X.; Lin, L.; Feder, R.; Johnson, D.; Watts, C.

    2013-04-15

    One of the systems planned for the measurement of electron density in ITER is a multi-channel tangentially viewing combined interferometer-polarimeter (TIP). This work discusses the current status of the design, including a preliminary optical table layout, calibration options, error sources, and performance projections based on a CO{sub 2}/CO laser system. In the current design, two-color interferometry is carried out at 10.59 {mu}m and 5.42 {mu}m and a separate polarimetry measurement of the plasma induced Faraday effect, utilizing the rotating wave technique, is made at 10.59 {mu}m. The inclusion of polarimetry provides an independent measure of the electron density and can also be used to correct the conventional two-color interferometer for fringe skips at all densities, up to and beyond the Greenwald limit. The system features five chords with independent first mirrors to reduce risks associated with deposition, erosion, etc., and a common first wall hole to minimize penetration sizes. Simulations of performance for a projected ITER baseline discharge show the diagnostic will function as well as, or better than, comparable existing systems for feedback density control. Calculations also show that finite temperature effects will be significant in ITER even for moderate temperature plasmas and can lead to a significant underestimate of electron density. A secondary role TIP will fulfill is that of a density fluctuation diagnostic; using a toroidal Alfven eigenmode as an example, simulations show TIP will be extremely robust in this capacity and potentially able to resolve coherent mode fluctuations with perturbed densities as low as {delta}n/n Almost-Equal-To 10{sup -5}.

  9. Development of ITER 15 MA ELMy H-mode Inductive Scenario

    SciTech Connect (OSTI)

    Kessel, C. E.; Campbell, D.; Gribov, Y.; Saibene, G.; Ambrosino, G.; Casper, T.; Cavinato, M.; Fujieda, H.; Hawryluk, R.; Horton, L. D.; Kavin, A.; Kharyrutdinov, R.; Koechl, F.; Leuer, J.; Loarte, A.; Lomas, P. J.; Luce, T.; Lukash, V.; Mattei, M.; Nunes, I.; Parail, V.; Polevoi, A.; Portone, A.; Sartori, R.; Sips, A. C.C.; Thomas, P. R.; Welander, A.; Wesley, J.

    2008-10-16

    The poloidal field (PF) coil system on ITER, which provides both feedforward and feedback control of plasma position, shape, and current, is a critical element for achieving mission performance. Analysis of PF capabilities has focused on the 15 MA Q = 10 scenario with a 300-500 s flattop burn phase. The operating space available for the 15 MA ELMy H-mode plasma discharges in ITER and upgrades to the PF coils or associated systems to establish confidence that ITER mission objectives can be reached have been identified. Time dependent self-consistent free-boundary calculations were performed to examine the impact of plasma variability, discharge programming, and plasma disturbances. Based on these calculations a new reference scenario was developed based upon a large bore initial plasma, early divertor transition, low level heating in L-mode, and a late H-mode onset. Equilibrium analyses for this scenario indicate that the original PF coil limitations do not allow low li (<0.8) operation or lower flux states, and the flattop burn durations were predicted to be less than the desired 400 s. This finding motivates the expansion of the operating space, considering several upgrade options to the PF coils. Analysis was also carried out to examine the feedback current reserve required in the CS and PF coils during a series of disturbances and a feasibility assessment of the 17 MA scenario was undertaken. Results of the studies show that the new scenario and modified PF system will allow a wide range of 15 MA 300-500 s operation and more limited but finite 17 MA operation.

  10. TU-F-18A-02: Iterative Image-Domain Decomposition for Dual-Energy CT

    SciTech Connect (OSTI)

    Niu, T; Dong, X; Petrongolo, M; Zhu, L

    2014-06-15

    Purpose: Dual energy CT (DECT) imaging plays an important role in advanced imaging applications due to its material decomposition capability. Direct decomposition via matrix inversion suffers from significant degradation of image signal-to-noise ratios, which reduces clinical value. Existing de-noising algorithms achieve suboptimal performance since they suppress image noise either before or after the decomposition and do not fully explore the noise statistical properties of the decomposition process. We propose an iterative image-domain decomposition method for noise suppression in DECT, using the full variance-covariance matrix of the decomposed images. Methods: The proposed algorithm is formulated in the form of least-square estimation with smoothness regularization. It includes the inverse of the estimated variance-covariance matrix of the decomposed images as the penalty weight in the least-square term. Performance is evaluated using an evaluation phantom (Catphan 600) and an anthropomorphic head phantom. Results are compared to those generated using direct matrix inversion with no noise suppression, a de-noising method applied on the decomposed images, and an existing algorithm with similar formulation but with an edge-preserving regularization term. Results: On the Catphan phantom, our method retains the same spatial resolution as the CT images before decomposition while reducing the noise standard deviation of decomposed images by over 98%. The other methods either degrade spatial resolution or achieve less low-contrast detectability. Also, our method yields lower electron density measurement error than direct matrix inversion and reduces error variation by over 97%. On the head phantom, it reduces the noise standard deviation of decomposed images by over 97% without blurring the sinus structures. Conclusion: We propose an iterative image-domain decomposition method for DECT. The method combines noise suppression and material decomposition into an iterative

  11. 3D automatic anatomy segmentation based on iterative graph-cut-ASM

    SciTech Connect (OSTI)

    Chen, Xinjian; Bagci, Ulas

    2011-08-15

    Purpose: This paper studies the feasibility of developing an automatic anatomy segmentation (AAS) system in clinical radiology and demonstrates its operation on clinical 3D images. Methods: The AAS system, the authors are developing consists of two main parts: object recognition and object delineation. As for recognition, a hierarchical 3D scale-based multiobject method is used for the multiobject recognition task, which incorporates intensity weighted ball-scale (b-scale) information into the active shape model (ASM). For object delineation, an iterative graph-cut-ASM (IGCASM) algorithm is proposed, which effectively combines the rich statistical shape information embodied in ASM with the globally optimal delineation capability of the GC method. The presented IGCASM algorithm is a 3D generalization of the 2D GC-ASM method that they proposed previously in Chen et al.[Proc. SPIE, 7259, 72590C1-72590C-8 (2009)]. The proposed methods are tested on two datasets comprised of images obtained from 20 patients (10 male and 10 female) of clinical abdominal CT scans, and 11 foot magnetic resonance imaging (MRI) scans. The test is for four organs (liver, left and right kidneys, and spleen) segmentation, five foot bones (calcaneus, tibia, cuboid, talus, and navicular). The recognition and delineation accuracies were evaluated separately. The recognition accuracy was evaluated in terms of translation, rotation, and scale (size) error. The delineation accuracy was evaluated in terms of true and false positive volume fractions (TPVF, FPVF). The efficiency of the delineation method was also evaluated on an Intel Pentium IV PC with a 3.4 GHZ CPU machine. Results: The recognition accuracies in terms of translation, rotation, and scale error over all organs are about 8 mm, 10 deg. and 0.03, and over all foot bones are about 3.5709 mm, 0.35 deg. and 0.025, respectively. The accuracy of delineation over all organs for all subjects as expressed in TPVF and FPVF is 93.01% and 0.22%, and

  12. X-ray crystal spectrometer upgrade for ITER-like wall experiments at JET

    SciTech Connect (OSTI)

    Shumack, A. E.; Rzadkiewicz, J.; Chernyshova, M.; Czarski, T.; Karpinski, L.; Jakubowska, K.; Scholz, M.; Byszuk, A.; Cieszewski, R.; Kasprowicz, G.; Pozniak, K.; Wojenski, A.; Zabolotny, W.; Dominik, W.; Conway, N. J.; Dalley, S.; Tyrrell, S.; Zastrow, K.-D.; Figueiredo, J. [EFDA-CSU, Culham Science Centre, Abingdon OX14 3DB; Associação EURATOM and others

    2014-11-15

    The high resolution X-Ray crystal spectrometer at the JET tokamak has been upgraded with the main goal of measuring the tungsten impurity concentration. This is important for understanding impurity accumulation in the plasma after installation of the JET ITER-like wall (main chamber: Be, divertor: W). This contribution provides details of the upgraded spectrometer with a focus on the aspects important for spectral analysis and plasma parameter calculation. In particular, we describe the determination of the spectrometer sensitivity: important for impurity concentration determination.

  13. Source term evaluation for accident transients in the experimental fusion facility ITER

    SciTech Connect (OSTI)

    Virot, F.; Barrachin, M.; Cousin, F.

    2015-03-15

    We have studied the transport and chemical speciation of radio-toxic and toxic species for an event of water ingress in the vacuum vessel of experimental fusion facility ITER with the ASTEC code. In particular our evaluation takes into account an assessed thermodynamic data for the beryllium gaseous species. This study shows that deposited beryllium dusts of atomic Be and Be(OH){sub 2} are formed. It also shows that Be(OT){sub 2} could exist in some conditions in the drain tank. (authors)

  14. Carbon charge exchange analysis in the ITER-like wall environment

    SciTech Connect (OSTI)

    Menmuir, S.; Giroud, C.; Hawkes, N. C.; Biewer, T. M.; Coffey, I. H.; Delabie, E.; Sertoli, M.

    2014-11-15

    Charge exchange spectroscopy has long been a key diagnostic tool for fusion plasmas and is well developed in devices with Carbon Plasma-Facing Components. Operation with the ITER-like wall at JET has resulted in changes to the spectrum in the region of the Carbon charge exchange line at 529.06 nm and demonstrates the need to revise the core charge exchange analysis for this line. An investigation has been made of this spectral region in different plasma conditions and the revised description of the spectral lines to be included in the analysis is presented.

  15. Development of the prototype pneumatic transfer system for ITER neutron activation system

    SciTech Connect (OSTI)

    Cheon, M. S.; Seon, C. R.; Pak, S.; Lee, H. G.; Bertalot, L.

    2012-10-15

    The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.

  16. Refinement of overlapping local/global iteration method based on Monte Carlo/p-CMFD calculations

    SciTech Connect (OSTI)

    Jo, Y.; Yun, S.; Cho, N. Z.

    2013-07-01

    In this paper, the overlapping local/global (OLG) iteration method based on Monte Carlo/p-CMFD calculations is refined in two aspects. One is the consistent use of estimators to generate homogenized scattering cross sections. Another is that the incident or exiting angular interval is divided into multi-angular bins to modulate albedo boundary conditions for local problems. Numerical tests show that, compared to the one angle bin case in a previous study, the four angle bin case shows significantly improved results. (authors)

  17. "Rip" Perkins, pioneering PPPL physicist and a design leader for ITER,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dies at 80 | Princeton Plasma Physics Lab "Rip" Perkins, pioneering PPPL physicist and a design leader for ITER, dies at 80 By John Greenwald August 11, 2014 Tweet Widget Google Plus One Share on Facebook Francis "Rip" Perkins Francis "Rip" Perkins Gallery: "Rip" Perkins, center, as head of the PPPL Theory Department with Wei-li Lee, left, and John Krommes, right. "Rip" Perkins, center, as head of the PPPL Theory Department with Wei-li Lee,

  18. "Rip" Perkins, pioneering PPPL physicist and a design leader for ITER,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dies at 80 | Princeton Plasma Physics Lab "Rip" Perkins, pioneering PPPL physicist and a design leader for ITER, dies at 80 By John Greenwald August 11, 2014 Tweet Widget Google Plus One Share on Facebook Francis "Rip" Perkins Francis "Rip" Perkins Gallery: "Rip" Perkins, center, as head of the PPPL Theory Department with Wei-li Lee, left, and John Krommes, right. "Rip" Perkins, center, as head of the PPPL Theory Department with Wei-li Lee,

  19. Note: Readout of a micromechanical magnetometer for the ITER fusion reactor

    SciTech Connect (OSTI)

    Rimminen, H.; Kyynaeraeinen, J.

    2013-05-15

    We present readout instrumentation for a MEMS magnetometer, placed 30 m away from the MEMS element. This is particularly useful when sensing is performed in high-radiation environment, where the semiconductors in the readout cannot survive. High bandwidth transimpedance amplifiers are used to cancel the cable capacitances of several nanofarads. A frequency doubling readout scheme is used for crosstalk elimination. Signal-to-noise ratio in the range of 60 dB was achieved and with sub-percent nonlinearity. The presented instrument is intended for the steady-state magnetic field measurements in the ITER fusion reactor.

  20. Engineer Russ Feder leads development of diagnostic tools for US ITER as

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    physicist Dave Johnson shifts to part-time work | Princeton Plasma Physics Lab Engineer Russ Feder leads development of diagnostic tools for US ITER as physicist Dave Johnson shifts to part-time work By John Greenwald March 16, 2015 Tweet Widget Google Plus One Share on Facebook Dave Johnson, left, and Russ Feder with design for component of a diagnostic system behind them. (Photo by Elle Starkman/PPPL Office of Communications) Dave Johnson, left, and Russ Feder with design for component of

  1. Engineer Russ Feder leads development of diagnostic tools for US ITER as

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    physicist Dave Johnson shifts to part-time work | Princeton Plasma Physics Lab Engineer Russ Feder leads development of diagnostic tools for US ITER as physicist Dave Johnson shifts to part-time work By John Greenwald March 16, 2015 Tweet Widget Google Plus One Share on Facebook Dave Johnson, left, and Russ Feder with design for component of a diagnostic system behind them. (Photo by Elle Starkman/PPPL Office of Communications) Dave Johnson, left, and Russ Feder with design for component of

  2. Using an iterative eigensolver to compute vibrational energies with phase-spaced localized basis functions

    SciTech Connect (OSTI)

    Brown, James Carrington, Tucker

    2015-07-28

    Although phase-space localized Gaussians are themselves poor basis functions, they can be used to effectively contract a discrete variable representation basis [A. Shimshovitz and D. J. Tannor, Phys. Rev. Lett. 109, 070402 (2012)]. This works despite the fact that elements of the Hamiltonian and overlap matrices labelled by discarded Gaussians are not small. By formulating the matrix problem as a regular (i.e., not a generalized) matrix eigenvalue problem, we show that it is possible to use an iterative eigensolver to compute vibrational energy levels in the Gaussian basis.

  3. Robust parallel iterative solvers for linear and least-squares problems, Final Technical Report

    SciTech Connect (OSTI)

    Saad, Yousef

    2014-01-16

    The primary goal of this project is to study and develop robust iterative methods for solving linear systems of equations and least squares systems. The focus of the Minnesota team is on algorithms development, robustness issues, and on tests and validation of the methods on realistic problems. 1. The project begun with an investigation on how to practically update a preconditioner obtained from an ILU-type factorization, when the coefficient matrix changes. 2. We investigated strategies to improve robustness in parallel preconditioners in a specific case of a PDE with discontinuous coefficients. 3. We explored ways to adapt standard preconditioners for solving linear systems arising from the Helmholtz equation. These are often difficult linear systems to solve by iterative methods. 4. We have also worked on purely theoretical issues related to the analysis of Krylov subspace methods for linear systems. 5. We developed an effective strategy for performing ILU factorizations for the case when the matrix is highly indefinite. The strategy uses shifting in some optimal way. The method was extended to the solution of Helmholtz equations by using complex shifts, yielding very good results in many cases. 6. We addressed the difficult problem of preconditioning sparse systems of equations on GPUs. 7. A by-product of the above work is a software package consisting of an iterative solver library for GPUs based on CUDA. This was made publicly available. It was the first such library that offers complete iterative solvers for GPUs. 8. We considered another form of ILU which blends coarsening techniques from Multigrid with algebraic multilevel methods. 9. We have released a new version on our parallel solver - called pARMS [new version is version 3]. As part of this we have tested the code in complex settings - including the solution of Maxwell and Helmholtz equations and for a problem of crystal growth.10. As an application of polynomial preconditioning we considered the

  4. Public Involvement and Communications Committee Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    3, 2011 FINAL WEBINAR SUMMARY HANFORD ADVISORY BOARD PUBLIC INVOLVEMENT & COMMUNICATIONS COMMITTEE MEETING October 3, 2011 Topics in this Meeting Summary Welcome, introductions, and webinar overview .......................................................................................... 1 Introduction to the preliminary draft Hanford Public Involvement Plan ..................................................... 2 Results of the Heart of America Northwest Public Involvement Survey

  5. Public Involvement and Communications Committee Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    11, 2011 FINAL MEETING SUMMARY HANFORD ADVISORY BOARD PUBLIC INVOLVEMENT & COMMUNICATIONS COMMITTEE MEETING October 11, 2011 Richland, WA Topics in this Meeting Summary Welcome and Introductions ............................................................................................................ 1 Draft Advice - Draft Hanford Public Involvement Plan ................................................................ 1 Public Meetings - Draft Hanford Public Involvement Plan

  6. Cyber Incidents Involving Control Systems

    SciTech Connect (OSTI)

    Robert J. Turk

    2005-10-01

    The Analysis Function of the US-CERT Control Systems Security Center (CSSC) at the Idaho National Laboratory (INL) has prepared this report to document cyber security incidents for use by the CSSC. The description and analysis of incidents reported herein support three CSSC tasks: establishing a business case; increasing security awareness and private and corporate participation related to enhanced cyber security of control systems; and providing informational material to support model development and prioritize activities for CSSC. The stated mission of CSSC is to reduce vulnerability of critical infrastructure to cyber attack on control systems. As stated in the Incident Management Tool Requirements (August 2005) ''Vulnerability reduction is promoted by risk analysis that tracks actual risk, emphasizes high risk, determines risk reduction as a function of countermeasures, tracks increase of risk due to external influence, and measures success of the vulnerability reduction program''. Process control and Supervisory Control and Data Acquisition (SCADA) systems, with their reliance on proprietary networks and hardware, have long been considered immune to the network attacks that have wreaked so much havoc on corporate information systems. New research indicates this confidence is misplaced--the move to open standards such as Ethernet, Transmission Control Protocol/Internet Protocol, and Web technologies is allowing hackers to take advantage of the control industry's unawareness. Much of the available information about cyber incidents represents a characterization as opposed to an analysis of events. The lack of good analyses reflects an overall weakness in reporting requirements as well as the fact that to date there have been very few serious cyber attacks on control systems. Most companies prefer not to share cyber attack incident data because of potential financial repercussions. Uniform reporting requirements will do much to make this information available to

  7. The influence of an ITER-like wall on disruptions at JET

    SciTech Connect (OSTI)

    Vries, P. C. de Hogeweij, G. M. D.; Baruzzo, M.; Murari, A.; Jachmich, S.; Lomas, P. J.; Matthews, G. F.; Pütterich, T.; Vega, J.; Collaboration: JET-EFDA Contributors

    2014-05-15

    In order to preserve the integrity of large tokamaks such as ITER, the number of disruptions has to be limited. JET has operated previously with a low frequency of disruptions (i.e., disruption rate) of 3.4% [P. C. de Vries et al., Nucl. Fusion 51, 053018 (2011)]. The start of operations with the new full-metal ITER-like wall at JET showed a marked rise in the disruption rate to 10%. A full survey was carried out to identify the root causes, the chain-of-events and classifying each disruption, similar to a previous analysis for carbon-wall operations. It showed the improvements made to avoid various disruption classes, but also indicated those disruption types responsible for the enhanced disruption rate. The latter can be mainly attributed to disruptions due to too high core radiation but also due to density control issues and error field locked modes. Detailed technical and physics understanding of disruption causes is essential for devising optimized strategies to avoid or mitigate these events.

  8. The targeted heating and current drive applications for the ITER electron cyclotron system

    SciTech Connect (OSTI)

    Henderson, M.; Darbos, C.; Gandini, F.; Gassmann, T.; Loarte, A.; Omori, T.; Purohit, D.; Saibene, G.; Gagliardi, M.; Farina, D.; Figini, L.; Hanson, G.; Poli, E.; Takahashi, K.

    2015-02-15

    A 24 MW Electron Cyclotron (EC) system operating at 170 GHz and 3600 s pulse length is to be installed on ITER. The EC plant shall deliver 20 MW of this power to the plasma for Heating and Current Drive (H and CD) applications. The EC system is designed for plasma initiation, central heating, current drive, current profile tailoring, and Magneto-hydrodynamic control (in particular, sawteeth and Neo-classical Tearing Mode) in the flat-top phase of the plasma. A preliminary design review was performed in 2012, which identified a need for extended application of the EC system to the plasma ramp-up, flattop, and ramp down phases of ITER plasma pulse. The various functionalities are prioritized based on those applications, which can be uniquely addressed with the EC system in contrast to other H and CD systems. An initial attempt has been developed at prioritizing the allocated H and CD applications for the three scenarios envisioned: ELMy H-mode (15 MA), Hybrid (∼12 MA), and Advanced (∼9 MA) scenarios. This leads to the finalization of the design requirements for the EC sub-systems.

  9. H-mode pedestal characteristics in ITER shape discharges on DIII-D

    SciTech Connect (OSTI)

    Osborne, T.H.; Burrell, K.H.; Groebner, R.J.

    1998-09-01

    Characteristics of the H-mode pedestal are studied in Type 1 ELM discharges with ITER cross-sectional shape and aspect ratio. The scaling of the width of the edge step gradient region, {delta}, which is most consistent with the data is with the normalized edge pressure, ({beta}{sub POL}{sup PED}){sup 0.4}. Fits of {delta} to a function of temperature, such as {rho}{sub POL}, are ruled out in divertor pumping experiments. The edge pressure gradient is found to scale as would be expected from infinite n ballooning mode theory; however, the value of the pressure gradient exceeds the calculated first stable limit by more than a factor of 2 in some discharges. This high edge pressure gradient is consistent with access to the second stable regime for ideal ballooning for surfaces near the edge. In lower q discharges, including discharges at the ITER value of q, edge second stability requires significant edge current density. Transport simulations give edge bootstrap current of sufficient magnitude to open second stable access in these discharges. Ideal kink analysis using current density profiles including edge bootstrap current indicate that before the ELM these discharges may be unstable to low n, edge localized modes.

  10. Development of a Twin-Screw D-2 Extruder for the ITER Pellet Injection System

    SciTech Connect (OSTI)

    Meitner, Steven J; Baylor, Larry R; Carbajo, Juan J; Combs, Stephen Kirk; Fehling, Dan T; Foust, Charles R; McFee, Marshall T; McGill, James M; Rasmussen, David A; Sitterson, R G; Sparks, Dennis O; Qualls, A L

    2009-07-01

    A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. The extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with single-stage gas gun into the plasma. A one-fifth ITER scale prototype extruder has been built to produce a continuous solid deuterium extrusion. Deuterium gas is precooled and liquefied before being introduced into the extruder. The precooler consists of a copper vessel containing liquid nitrogen surrounded by a deuterium gas filled copper coil. The liquefier is comprised of a copper cylinder connected to a Cryomech AL330 cryocooler, which is surrounded by a copper coil that the precooled deuterium flows through. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at approximate to 15 K) before it is forced through the extruder nozzle. A viewport located below the extruder nozzle provides a direct view of the extrusion. A camera is used to document the extrusion quality and duration. A data acquisition system records the extruder temperatures, torque, and speed, upstream, and downstream pressures. This paper will describe the prototype twin-screw extruder and initial extrusion results.

  11. ITER Core Imaging X-Ray Spectrometer Conceptual Design and Performance Assessment - Phase 2

    SciTech Connect (OSTI)

    Beiersdorfer, P; Wen, J; Dunn, J; Morris, K

    2011-01-02

    During Phase 2 of our study of the CIXS conceptual design we have tackled additional important issues that are unique to the ITER environment. These include the thermal control of the crystal and detector enclosures located in an environment with a 100-250 C ambient temperature, tritium containment, and the range of crystal and detector movement based on the need for spectral adjustments and the desire to make measurements of colder plasmas. In addressing these issues we have selected a ''Dewar''-type enclosure for the crystals and detectors. Applying realistic view factors for radiant heat and making allowance for conduction we have made engineering studies of this enclosure and showed that the cooling requirements can be solved and the temperature can be kept sufficiently constant without compromising the specification parameters of the CIXS. We have chosen a minimum 3 mm combined thickness of the six beryllium windows needed in a Dewar-type enclosure and showed that a single window of 0.5 mm thickness satisfies tritium containment requirements. For measuring the temperature in cooler ITER plasmas, we have chosen to use the K-shell lines of Fe24+. Iron is the preferred choice because its radiation can be analyzed with the identical CIXS settings used for analyzing the tungsten radiation, i.e., essentially no adjustments besides a simple crystal rotation need to be made. We have, however, included an xy{theta}-drive motor arrangement in our design for fine adjustments and full rotation of the crystal mounts.

  12. Workplace Charging Challenge Partner: JLA Public Involvement...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Purchasing a plug-in electric vehicle (PEV) and installing a charging station has expanded JLA Public Involvement's sustainability efforts and allowed them to achieve Gold ...

  13. Central Plateau Principles Public Involvement Advice DETAILED...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    v0, 12914 Central Plateau Principles Public Involvement Advice DETAILED BACKGROUND Cleanup of Hanford's Central Plateau is expected to take another four decades or longer, and...

  14. Public Involvement and Communications Committee Summaries - Hanford...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    05, 2012 Final Attachment 1: Tri-Party Agreement Agencies - Public Involvement Calendar Fiscal Year 2012 - not available Attachment 2: PIC Meeting Transcribed Flip Chart Notes...

  15. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Modeling & Analysis, News, News & Events, Photovoltaic, Renewable Energy, Research & Capabilities, Solar, Solar Newsletter, SunShot, Systems Analysis Sandia Develops Stochastic ...

  16. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Monte Carlo modeling it was found that for noisy signals with a significant background component, accuracy is improved by fitting the total emission data which includes the...

  17. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solar Sandia Labs Releases New Version of PVLib Toolbox Sandia has released version 1.3 of PVLib, its widely used Matlab toolbox for modeling photovoltaic (PV) power ...

  18. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... Sandia Will Host PV Bankability Workshop at Solar Power International (SPI) 2013 Computational Modeling & Simulation, Distribution Grid Integration, Energy, Facilities, Grid ...

  19. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Science and Actuarial Practice" Read More Permalink New Project Is the ACME of Computer Science to Address Climate Change Analysis, Climate, Global Climate & Energy, Modeling, ...

  20. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Though adequate for modeling mean transport, this approach does not address ... Microphysics such as diffusive transport and chemical kinetics are represented by ...

  1. Study of the choice of the decoupling layout for the ITER ICRH system

    SciTech Connect (OSTI)

    Vervier, M. Messiaen, A.; Ongena, J.; Durodié, F.

    2015-12-10

    10 decouplers are used to neutralize the mutual coupling effects and to control the current amplitude of the 24 straps array of the ITER ICRH antenna in the case of current drive phasing. In the case of heating phasing only 4 decouplers are active and the array current control needs to act on the ratio between the power delivered by the 4 generators. This ratio is very sensitive to the precise adjustment of the antenna array phasing. The maximum total radiated power capability is then limited when the power of one generator reaches its maximum value. With the addition of four switches all 10 installed decouplers are made active and can act on all mutual coupling effects with equal source power from the 4 generators. With four more switches the current drive phasing could work with a reduced poloidal phasing resulting in a 35% increase of its coupling to the plasma.

  2. Design Analysis and Manufacturing Studies for ITER In-Vessel Coils

    SciTech Connect (OSTI)

    Kalish, M.; Heitzenroeder, P.; Neumeyer, C.; Titus, P.; Zhai, Y.; Zatz, I.; Messineo, M.; Gomez, M.; Hause, C.; Daly, E.; Martin, A.; Wu, Y.; Jin, J.; Long, F.; Song, Y.; Wang, Z.; Yun, Zan; Hsiao, J.; Pillsbury, J. R.; Bohm, T.; Sawan, M.; Jiang, NFN

    2014-07-01

    ITER is incorporating two types of In Vessel Coils (IVCs): ELM Coils to mitigate Edge Localized Modes and VS Coils to provide Vertical Stabilization of the plasma. Strong coupling with the plasma is required so that the ELM and VS Coils can meet their performance requirements. Accordingly, the IVCs are in close proximity to the plasma, mounted just behind the Blanket Shield Modules. This location results in a radiation and temperature environment that is severe necessitating new solutions for material selection as well as challenging analysis and design solutions. Fitting the coil systems in between the blanket shield modules and the vacuum vessel leads to difficult integration with diagnostic cabling and cooling water manifolds.

  3. The development of in-situ calibration method for divertor IR thermography in ITER

    SciTech Connect (OSTI)

    Takeuchi, M.; Sugie, T.; Ogawa, H.; Takeyama, S.; Itami, K.

    2014-08-21

    For the development of the calibration method of the emissivity in IR light on the divertor plate in ITER divertor IR thermography system, the laboratory experiments have been performed by using IR instruments. The calibration of the IR camera was performed by the plane black body in the temperature of 100–600 degC. The radiances of the tungsten heated by 280 degC were measured by the IR camera without filter (2.5–5.1 μm) and with filter (2.95 μm, 4.67 μm). The preliminary data of the scattered light of the laser of 3.34 μm that injected into the tungsten were acquired.

  4. FETI Prime Domain Decomposition base Parallel Iterative Solver Library Ver.1.0

    Energy Science and Technology Software Center (OSTI)

    2003-09-15

    FETI Prime is a library for the iterative solution of linear equations in solid and structural mechanics. The algorithm employs preconditioned conjugate gradients, with a domain decomposition-based preconditioner. The software is written in C++ and is designed for use with massively parallel computers, using MPI. The algorithm is based on the FETI-DP method, with additional capabilities for handling constraint equations, as well as interfacing with the Salinas structural dynamics code and the Finite Element Interfacemore » (FEI) library. Practical Application: FETI Prime is designed for use with finite element-based simulation codes for solid and structural mechanics. The solver uses element matrices, connectivity information, nodal information, and force vectors computed by the host code and provides back the solution to the linear system of equations, to the user specified level of accuracy, The library is compiled with the host code and becomes an integral part of the host code executable.« less

  5. Iterative Monte Carlo analysis of spin-dependent parton distributions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sato, Nobuo; Melnitchouk, Wally; Kuhn, Sebastian E.; Ethier, Jacob J.; Accardi, Alberto

    2016-04-05

    We present a comprehensive new global QCD analysis of polarized inclusive deep-inelastic scattering, including the latest high-precision data on longitudinal and transverse polarization asymmetries from Jefferson Lab and elsewhere. The analysis is performed using a new iterative Monte Carlo fitting technique which generates stable fits to polarized parton distribution functions (PDFs) with statistically rigorous uncertainties. Inclusion of the Jefferson Lab data leads to a reduction in the PDF errors for the valence and sea quarks, as well as in the gluon polarization uncertainty at x ≳ 0.1. Furthermore, the study also provides the first determination of the flavor-separated twist-3 PDFsmore » and the d2 moment of the nucleon within a global PDF analysis.« less

  6. Benchmarking MELCOR 1.8.2 for ITER Against Recent EVITA Results

    SciTech Connect (OSTI)

    Merrill, Brad J

    2007-11-01

    A version of MELCOR 1.8.2 modified for use in ITER Preliminary Safety Report analyses was validated against recent data from the EVITA facility located in Cadarache, France. EVITA Test Series 7 was used for this study to verify MELCOR’s ability to predict the pressures, temperatures, cryoplate ice mass, and vaccum vessel (VV) condensate mass for test conditions in EVITA that include injections of steam, nitrogen, and water in to the EVITA VV after the walls had been heated to 165 ºC and the cryoplate had been cooled to -193 ºC. In general, the ability of MELCOR to predict the VV pressure and wall temperatures for the steam only and water only injection tests was very good. Predicted ice layer masses where larger than reported for the EVITA cryoplate, in particular for the steam only injection tests (~40% too high), and the predicted condensate masses were less that measured in EVITA. Both of these descrpancies can be explained by ice porosity. The modified MELCOR 1.8.2 over predicts the EVITA VV pressure for the co-injection tests (e.g., steam plus nitrogen, or water plus nitrogen injections) by almost a factor of two. Based on parametric runs that where made by increasing the predicted cryoplate condensation rate, it is believed that this pressure over prediction is a result of an under predicted cryoplate condensation rate. The particulars of this study are documented in this report as well as conclusions about the impact this study has regarding the use of this verions of MELCOR for consequence analyses for ITER safety reports.

  7. Real-time sawtooth control and neoclassical tearing mode preemption in ITER

    SciTech Connect (OSTI)

    Kim, D. Goodman, T. P.; Sauter, O.

    2014-06-15

    Real-time control of multiple plasma actuators is a requirement in advanced tokamaks; for example, for burn control, plasma current profile control and MHD stabilization—electron cyclotron (EC) wave absorption is ideally suited especially for the latter. On ITER, 24 EC sources can be switched between 56 inputs at the torus. In the torus, 5 launchers direct the power to various locations across the plasma profile via 11 steerable mirrors. For optimal usage of the available power, the aiming and polarization of the beams must be adapted to the plasma configuration and the needs of the scenario. Since the EC system performs many competing tasks, present day systems should demonstrate the ability of an EC plant to deal with several targets in parallel and/or to switch smoothly between goals to attain overall satisfaction. Based on pacing and locking experiments performed on TCV (Tokamak à Configuration Variable), the real-time sawtooth control of ITER with this complex set of actuators is analyzed, as an example. It is shown that sawtooth locking and pacing are possible with various levels of powers, leading to different time delays between the end of the EC power phase and the next sawtooth crash. This timing is important since it allows use of the same launchers for neoclassical tearing mode (NTM) preemption at the q = 1.5 or 2 surface, avoiding the need to switch power between launchers. These options are presented. It is also demonstrated that increasing the total EC power does not necessarily increase the range of control because of the geometry of the launchers.

  8. Evaluation of Static Mixer Flow Enhancements for Cryogenic Viscous Compressor Prototype for ITER Vacuum System

    SciTech Connect (OSTI)

    Duckworth, Robert C; Baylor, Larry R; Meitner, Steven J; Combs, Stephen Kirk; Ha, Tam T; Morrow, Michael; Biewer, Theodore M; Rasmussen, David A; Hechler, Michael P; Pearce, R.J.H.; Dremel, M.; Boissin, Jean Claude

    2014-01-01

    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (50 to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype

  9. Evaluation of static mixer flow enhancements for cryogenic viscous compressor prototype for ITER vacuum system

    SciTech Connect (OSTI)

    Duckworth, Robert C.; Baylor, Larry R.; Meitner, Steven J.; Combs, Stephen K.; Ha, Tam; Morrow, Michael; Biewer, T.; Rasmussen, David A.; Hechler, Michael P.; Pearce, Robert J. H.; Dremel, Mattias; Boissin, J.-C.

    2014-01-29

    As part of the U.S. ITER contribution to the vacuum systems for the ITER fusion project, a cryogenic viscous compressor (CVC) is being designed and fabricated to cryopump hydrogenic gases in the torus and neutral beam exhaust streams and to regenerate the collected gases to controlled pressures such that they can be mechanically pumped with controlled flows to the tritium reprocessing facility. One critical element of the CVC design that required additional investigation was the determination of flow rates of the low pressure (up to 1000 Pa) exhaust stream that would allow for complete pumping of hydrogenic gases while permitting trace levels of helium to pass through the CVC to be pumped by conventional vacuum pumps. A sub-scale prototype test facility was utilized to determine the effectiveness of a static mixer pump tube concept, which consisted of a series of rotated twisted elements brazed into a 2-mm thick, 5-cm diameter stainless steel tube. Cold helium gas flow provided by a dewar and helium transfer line was used to cool the exterior of the static mixer pump tube. Deuterium gas was mixed with helium gas through flow controllers at different concentrations while the composition of the exhaust gas was monitored with a Penning gauge and optical spectrometer to determine the effectiveness of the static mixer. It was found that with tube wall temperatures between 6 K and 9 K, the deuterium gas was completely cryopumped and only helium passed through the tube. These results have been used to design the cooling geometry and the static mixer pump tubes in the full-scale CVC prototype.

  10. Ultralow dose computed tomography attenuation correction for pediatric PET CT using adaptive statistical iterative reconstruction

    SciTech Connect (OSTI)

    Brady, Samuel L.; Shulkin, Barry L.

    2015-02-15

    Purpose: To develop ultralow dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultralow doses (10–35 mA s). CT quantitation: noise, low-contrast resolution, and CT numbers for 11 tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% volume computed tomography dose index (0.39/3.64; mGy) from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed with the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUV{sub bw}) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative dose reduction and noise control. Results: CT numbers were constant to within 10% from the nondose reduced CTAC image for 90% dose reduction. No change in SUV{sub bw}, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols was found down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62% and 86% (3.2/8.3–0.9/6.2). Noise magnitude in dose-reduced patient images increased but was not statistically different from predose-reduced patient images. Conclusions: Using ASiR allowed for aggressive reduction in CT dose with no change in PET reconstructed images while maintaining sufficient image quality for colocalization of hybrid CT anatomy and PET radioisotope uptake.

  11. Mound Site Community Involvement Plan 2012

    Office of Legacy Management (LM)

    Involvement Plan for the U.S. Department of Energy Mound, Ohio, Site January 2015 LMS/MND/S02885-0.0 This page intentionally left blank U.S. Department of Energy Mound Community Involvement Plan January 2015 Doc. No. S02885-0.0 Page i Contents Abbreviations .................................................................................................................................. ii 1.0 Purpose and Introduction

  12. Public Involvement and Communications Committee Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    November 2, 2011 FINAL MEETING SUMMARY HANFORD ADVISORY BOARD PUBLIC INVOLVEMENT & COMMUNICATIONS COMMITTEE MEETING November 2, 2011 Kennewick, WA Topics in this Meeting Summary Welcome and Introductions ............................................................................................................ 1 Responses to Board Advice 239 and 240 ....................................................................................... 1 Public Involvement for the Hanford Site-wide Permit

  13. Scalable Nonlinear Solvers for Fully Implicit Coupled Nuclear Fuel Modeling. Final Report

    SciTech Connect (OSTI)

    Cai, Xiao-Chuan; Keyes, David; Yang, Chao; Zheng, Xiang; Pernice, Michael

    2014-09-29

    The focus of the project is on the development and customization of some highly scalable domain decomposition based preconditioning techniques for the numerical solution of nonlinear, coupled systems of partial differential equations (PDEs) arising from nuclear fuel simulations. These high-order PDEs represent multiple interacting physical fields (for example, heat conduction, oxygen transport, solid deformation), each is modeled by a certain type of Cahn-Hilliard and/or Allen-Cahn equations. Most existing approaches involve a careful splitting of the fields and the use of field-by-field iterations to obtain a solution of the coupled problem. Such approaches have many advantages such as ease of implementation since only single field solvers are needed, but also exhibit disadvantages. For example, certain nonlinear interactions between the fields may not be fully captured, and for unsteady problems, stable time integration schemes are difficult to design. In addition, when implemented on large scale parallel computers, the sequential nature of the field-by-field iterations substantially reduces the parallel efficiency. To overcome the disadvantages, fully coupled approaches have been investigated in order to obtain full physics simulations.

  14. Modelling of edge localised modes and edge localised mode control [Modelling of ELMs and ELM control

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huijsmans, G. T. A.; Chang, C. S.; Ferraro, N.; Sugiyama, L.; Waelbroeck, F.; Xu, X. Q.; Loarte, A.; Futatani, S.

    2015-02-07

    Edge Localised Modes (ELMs) in ITER Q = 10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. In order to avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field perturbations created by in-vessel coils and the injection of small D2 pellets. ITER plasmas are characterised by low collisionality at a high density (high fraction of the Greenwald density limit). These parameters cannot simultaneously be achieved in current experiments. Thus, the extrapolation of the ELM properties andmore » the requirements for ELM control in ITER relies on the development of validated physics models and numerical simulations. Here, we describe the modelling of ELMs and ELM control methods in ITER. The aim of this paper is not a complete review on the subject of ELM and ELM control modelling but rather to describe the current status and discuss open issues.« less

  15. Multiphysics Engineering Analysis for an Integrated Design of ITER Diagnostic First Wall and Diagnostic Shield Module Design

    SciTech Connect (OSTI)

    Zhai, Y.; Loesser, G.; Smith, M.; Udintsev, V.; Giacomin, T., T.; Khodak, A.; Johnson, D,; Feder, R,

    2015-07-01

    ITER diagnostic first walls (DFWs) and diagnostic shield modules (DSMs) inside the port plugs (PPs) are designed to protect diagnostic instrument and components from a harsh plasma environment and provide structural support while allowing for diagnostic access to the plasma. The design of DFWs and DSMs are driven by 1) plasma radiation and nuclear heating during normal operation 2) electromagnetic loads during plasma events and associate component structural responses. A multi-physics engineering analysis protocol for the design has been established at Princeton Plasma Physics Laboratory and it was used for the design of ITER DFWs and DSMs. The analyses were performed to address challenging design issues based on resultant stresses and deflections of the DFW-DSM-PP assembly for the main load cases. ITER Structural Design Criteria for In-Vessel Components (SDC-IC) required for design by analysis and three major issues driving the mechanical design of ITER DFWs are discussed. The general guidelines for the DSM design have been established as a result of design parametric studies.

  16. Application of the Jacobian-Free Newton-Krylov Method to Nonlinear Acceleration of Transport Source Iteration in Slab Geometry

    SciTech Connect (OSTI)

    Dana A. Knoll; H. Park; Kord Smith

    2011-02-01

    The use of the Jacobian-free Newton-Krylov (JFNK) method within the context of nonlinear diffusion acceleration (NDA) of source iteration is explored. The JFNK method is a synergistic combination of Newton's method as the nonlinear solver and Krylov methods as the linear solver. JFNK methods do not form or store the Jacobian matrix, and Newton's method is executed via probing the nonlinear discrete function to approximate the required matrix-vector products. Current application of NDA relies upon a fixed-point, or Picard, iteration to resolve the nonlinearity. We show that the JFNK method can be used to replace this Picard iteration with a Newton iteration. The Picard linearization is retained as a preconditioner. We show that the resulting JFNK-NDA capability provides benefit in some regimes. Furthermore, we study the effects of a two-grid approach, and the required intergrid transfers when the higher-order transport method is solved on a fine mesh compared to the low-order acceleration problem.

  17. The ITER VIS/IR wide angle viewing system: Challenges and on-going R and D

    SciTech Connect (OSTI)

    Travere, J. M.; Aumeunier, M. H.; Joanny, M.; Jouve, M.; Martin, V.; Moncada, V.; Salasca, S.; Marot, L.; Chabaud, D.; Ferme, J. J.; Bremond, F.; Thonnat, M.

    2011-07-01

    The ITER tokamak is the next generation fusion device which will allow studying burning plasma obtained by a Deuterium-Tritium (D-T) fusion reaction during hundreds of seconds. ITER vacuum vessel real-time protection will be mandatory during plasma operation to avoid water leaks and critical plasma facing components degradation. The protection system will be based on a wide angle viewing system (WAVS) composed with 18 visible (VIS) and 18 infrared (IR) cameras covering 80 % of the vacuum vessel which will be one of the major imaging systems of ITER. Compared to protection systems routinely used on current tokamaks and based on imaging (VIS and/or IR), new constraints must be taken into account because of their influence on the system performance: the harsh environment (high neutron flux) and the metallic plasma facing components (both first wall and divertor). In this new demanding context, we have achieved three mandatory R and D studies starting from the understanding of the source of signals by using realistic photonic simulation up to real-time processing strategy taken into account first order optical design constraints to define what type of performance could be reached for ITER vacuum vessel protection. (authors)

  18. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    with application in modeling NDCX-II experiments Wangyi Liu 1 , John Barnard 2 , Alex Friedman 2 , Nathan Masters 2 , Aaron Fisher 2 , Alice Koniges 2 , David Eder 2 1 LBNL, USA, 2...

  19. Modeling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NASA Earth at Night Video EC, Energy, Energy Efficiency, Global, Modeling, News & Events, Solid-State Lighting, Videos NASA Earth at Night Video Have you ever wondered what the ...

  20. Coupling the Mixed Potential and Radiolysis Models for Used Fuel Degradation

    SciTech Connect (OSTI)

    Buck, Edgar C.; Jerden, James L.; Ebert, William L.; Wittman, Richard S.

    2013-08-30

    The primary purpose of this report is to describe the strategy for coupling three process level models to produce an integrated Used Fuel Degradation Model (FDM). The FDM, which is based on fundamental chemical and physical principals, provides direct calculation of radionuclide source terms for use in repository performance assessments. The G-value for H2O2 production (Gcond) to be used in the Mixed Potential Model (MPM) (H2O2 is the only radiolytic product presently included but others will be added as appropriate) needs to account for intermediate spur reactions. The effects of these intermediate reactions on [H2O2] are accounted for in the Radiolysis Model (RM). This report details methods for applying RM calculations that encompass the effects of these fast interactions on [H2O2] as the solution composition evolves during successive MPM iterations and then represent the steady-state [H2O2] in terms of an effective instantaneous or conditional generation value (Gcond). It is anticipated that the value of Gcond will change slowly as the reaction progresses through several iterations of the MPM as changes in the nature of fuel surface occur. The Gcond values will be calculated with the RM either after several iterations or when concentrations of key reactants reach threshold values determined from previous sensitivity runs. Sensitivity runs with RM indicate significant changes in G-value can occur over narrow composition ranges. The objective of the mixed potential model (MPM) is to calculate the used fuel degradation rates for a wide range of disposal environments to provide the source term radionuclide release rates for generic repository concepts. The fuel degradation rate is calculated for chemical and oxidative dissolution mechanisms using mixed potential theory to account for all relevant redox reactions at the fuel surface, including those involving oxidants produced by solution radiolysis and provided by the radiolysis model (RM). The RM calculates the

  1. Strategic Public Involvement Products For Review

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Public Involvement Products For Review PIC Discussion September 4, 2013 1 This list is from July 7, 2010 before we had decided on writing advice and is purely for reference for...

  2. Public Involvement and Communications Committee Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    January 13, 2011 FINAL MEETING SUMMARY HANFORD ADVISORY BOARD PUBLIC INVOLVEMENT & COMMUNICATIONS COMMITTEE MEETING January 13, 2011 Richland, WA Topics in this Meeting Summary Welcome and Introductions ............................................................................................................ 1 State of the Site Meetings ............................................................................................................... 2 Open Government Plan Advice

  3. Department of Energy Idaho - Public Involvement Opportunity

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Public Involvement Opportunity Public Involvement Opportunities Free Acrobat Reader Link Many of the documents provided are in the Adobe PDF format. If you do not have the latest version or do not have the Acrobat Reader, you may download the Reader FREE by clicking on the icon at left. If you experience problems in reading the files please down load the latest free Adobe® Reader. Current Documents for Review and Public Comment: Idaho-Related National Environmental Policy Act (NEPA) Documents

  4. Optimization of tritium breeding and shielding analysis to plasma in ITER fusion reactor

    SciTech Connect (OSTI)

    Indah Rosidah, M. Suud, Zaki; Yazid, Putranto Ilham

    2015-09-30

    The development of fusion energy is one of the important International energy strategies with the important milestone is ITER (International Thermonuclear Experimental Reactor) project, initiated by many countries, such as: America, Europe, and Japan who agreed to set up TOKAMAK type fusion reactor in France. In ideal fusion reactor the fuel is purely deuterium, but it need higher temperature of reactor. In ITER project the fuels are deuterium and tritium which need lower temperature of the reactor. In this study tritium for fusion reactor can be produced by using reaction of lithium with neutron in the blanket region. With the tritium breeding blanket which react between Li-6 in the blanket with neutron resulted from the plasma region. In this research the material used in each layer surrounding the plasma in the reactor is optimized. Moreover, achieving self-sufficiency condition in the reactor in order tritium has enough availability to be consumed for a long time. In order to optimize Tritium Breeding Ratio (TBR) value in the fusion reactor, there are several strategies considered here. The first requirement is making variation in Li-6 enrichment to be 60%, 70%, and 90%. But, the result of that condition can not reach TBR value better than with no enrichment. Because there is reduction of Li-7 percent when increasing Li-6 percent. The other way is converting neutron multiplier material with Pb. From this, we get TBR value better with the Be as neutron multiplier. Beside of TBR value, fusion reactor can analyze the distribution of neutron flux and dose rate of neutron to know the change of neutron concentration for each layer in reactor. From the simulation in this study, 97% neutron concentration can be absorbed by material in reactor, so it is good enough. In addition, it is required to analyze spectrum neutron energy in many layers in the fusion reactor such as in blanket, coolant, and divertor. Actually material in that layer can resist in high temperature

  5. Research on long pulse ECRH system of EAST in support of ITER

    SciTech Connect (OSTI)

    Wang, Xiaojie Liu, Fukun; Shan, Jiafang; Xu, Handong; Wu, Dajun; Li, Bo; Tang, Yunying; Zhang, Liyuan; Xu, Weiye; Hu, Huaichuan; Wang, Jiang; Yang, Yong; Xu, Li; Ma, Wendong; Feng, Jianqiang; Wei, Wei

    2015-12-10

    Experimental Advanced Superconducting Tokamak (EAST), as a fully superconducting tokamak in China, aims to achieve high performance plasma under steady-state operation. To fulfill the physical objectives of EAST, a program of 4-MW long pulse electron cyclotron resonance heating and current drive (EC H&CD) system, which would offer greater flexibility for plasma shape and plasma stabilization has been launched on EAST since 2011. The system, composed of 4 gyrotrons with nominal 1MW output power and 1000s pulse length each, is designed with the feature of steerable power handling capabilities at 140 GHz, using second harmonic of the extraordinary mode(X2). The missions of the ECRH system are to provide plasma heating, current drive, plasma profile tailoring and control of magneto-hydrodynamic (MHD) instabilities. Presently, the first two 140-GHz 1-MW gyrotrons, provided by GYCOM and CPI, respectively, have been tested at long pulse operation. The tubes, the associated power supplies, cooling system, cryogenic plant, 2 transmission lines and an equatorial launcher are now installed at EAST. The power generated from each tube will be transmitted by an evacuated corrugated waveguide transmission line and injected into plasma from the low field side (radial port) through a front steering equatorial launcher. Considering the diverse applications of the EC system, the beam’s launch angles can be continuously varied with the optimized scanning range of over 30° in poloidal direction and ±25° in toroidal, as well as the polarization could be adjusted during the discharge by the orientations of a pair of polarizers in the transmission line to maintain the highest absorption for different operational scenarios. The commissioning of the first 2MW ECRH plant for EAST is under way. The design, R&D activities and recent progress of the long pulse 140-GHz ECRH system are presented in this paper. As the technological requirements for EAST ECRH have many similarities with ITER

  6. Evaluating the performance of two neutron spectrum unfolding codes based on iterative procedures and artificial neural networks

    SciTech Connect (OSTI)

    Ortiz-Rodriguez, J. M.; Reyes Alfaro, A.; Reyes Haro, A.; Solis Sanches, L. O.; Miranda, R. Castaneda; Cervantes Viramontes, J. M.; Vega-Carrillo, H. R.

    2013-07-03

    In this work the performance of two neutron spectrum unfolding codes based on iterative procedures and artificial neural networks is evaluated. The first one code based on traditional iterative procedures and called Neutron spectrometry and dosimetry from the Universidad Autonoma de Zacatecas (NSDUAZ) use the SPUNIT iterative algorithm and was designed to unfold neutron spectrum and calculate 15 dosimetric quantities and 7 IAEA survey meters. The main feature of this code is the automated selection of the initial guess spectrum trough a compendium of neutron spectrum compiled by the IAEA. The second one code known as Neutron spectrometry and dosimetry with artificial neural networks (NDSann) is a code designed using neural nets technology. The artificial intelligence approach of neural net does not solve mathematical equations. By using the knowledge stored at synaptic weights on a neural net properly trained, the code is capable to unfold neutron spectrum and to simultaneously calculate 15 dosimetric quantities, needing as entrance data, only the rate counts measured with a Bonner spheres system. Similarities of both NSDUAZ and NSDann codes are: they follow the same easy and intuitive user's philosophy and were designed in a graphical interface under the LabVIEW programming environment. Both codes unfold the neutron spectrum expressed in 60 energy bins, calculate 15 dosimetric quantities and generate a full report in HTML format. Differences of these codes are: NSDUAZ code was designed using classical iterative approaches and needs an initial guess spectrum in order to initiate the iterative procedure. In NSDUAZ, a programming routine was designed to calculate 7 IAEA instrument survey meters using the fluence-dose conversion coefficients. NSDann code use artificial neural networks for solving the ill-conditioned equation system of neutron spectrometry problem through synaptic weights of a properly trained neural network. Contrary to iterative procedures, in neural

  7. Optimization of the ITER electron cyclotron equatorial launcher for improved heating and current drive functional capabilities

    SciTech Connect (OSTI)

    Farina, D.; Figini, L.; Henderson, M.; Saibene, G.

    2014-06-15

    The design of the ITER Electron Cyclotron Heating and Current Drive (EC H and CD) system has evolved in the last years both in goals and functionalities by considering an expanded range of applications. A large effort has been devoted to a better integration of the equatorial and the upper launchers, both from the point of view of the performance and of the design impact on the engineering constraints. However, from the analysis of the ECCD performance in two references H-mode scenarios at burn (the inductive H-mode and the advanced non-inductive scenario), it was clear that the EC power deposition was not optimal for steady-state applications in the plasma region around mid radius. An optimization study of the equatorial launcher is presented here aiming at removing this limitation of the EC system capabilities. Changing the steering of the equatorial launcher from toroidal to poloidal ensures EC power deposition out to the normalized toroidal radius ρ ≈ 0.6, and nearly doubles the EC driven current around mid radius, without significant performance degradation in the core plasma region. In addition to the improved performance, the proposed design change is able to relax some engineering design constraints on both launchers.

  8. Performance evaluation approach for the supercritical helium cold circulators of ITER

    SciTech Connect (OSTI)

    Vaghela, H.; Sarkar, B.; Bhattacharya, R.; Kapoor, H.; Chalifour, M.; Chang, H.-S.; Serio, L.

    2014-01-29

    The ITER project design foresees Supercritical Helium (SHe) forced flow cooling for the main cryogenic components, namely, the superconducting (SC) magnets and cryopumps (CP). Therefore, cold circulators have been selected to provide the required SHe mass flow rate to cope with specific operating conditions and technical requirements. Considering the availability impacts of such machines, it has been decided to perform evaluation tests of the cold circulators at operating conditions prior to the series production in order to minimize the project technical risks. A proposal has been conceptualized, evaluated and simulated to perform representative tests of the full scale SHe cold circulators. The objectives of the performance tests include the validation of normal operating condition, transient and off-design operating modes as well as the efficiency measurement. A suitable process and instrumentation diagram of the test valve box (TVB) has been developed to implement the tests at the required thermodynamic conditions. The conceptual engineering design of the TVB has been developed along with the required thermal analysis for the normal operating conditions to support the performance evaluation of the SHe cold circulator.

  9. Wide-angle ITER-prototype tangential infrared and visible viewing system for DIII-D

    SciTech Connect (OSTI)

    Lasnier, C. J. Allen, S. L.; Ellis, R. E.; Fenstermacher, M. E.; McLean, A. G.; Meyer, W. H.; Morris, K.; Seppala, L. G.; Crabtree, K.; Van Zeeland, M. A.

    2014-11-15

    An imaging system with a wide-angle tangential view of the full poloidal cross-section of the tokamak in simultaneous infrared and visible light has been installed on DIII-D. The optical train includes three polished stainless steel mirrors in vacuum, which view the tokamak through an aperture in the first mirror, similar to the design concept proposed for ITER. A dichroic beam splitter outside the vacuum separates visible and infrared (IR) light. Spatial calibration is accomplished by warping a CAD-rendered image to align with landmarks in a data image. The IR camera provides scrape-off layer heat flux profile deposition features in diverted and inner-wall-limited plasmas, such as heat flux reduction in pumped radiative divertor shots. Demonstration of the system to date includes observation of fast-ion losses to the outer wall during neutral beam injection, and shows reduced peak wall heat loading with disruption mitigation by injection of a massive gas puff.

  10. On the effects of using the GTH method in the iterative-aggregation disaggregation technique

    SciTech Connect (OSTI)

    Dayar, T.; Stewart, W.J.

    1994-12-31

    The iterative aggregation-disaggregation (IAD) technique is an effective method for solving finite nearly completely decomposable (NCD) Markov chains. Small perturbations in the transition probabilities of these chains lead to a considerable change in the stationary vector. Therefore, NCD Markov chains are referred to as being ill-conditioned. During an IAD step, this undesirable condition is inherited by the coupling matrix and one confronts the problem of finding the stationary vector of a stochastic matrix which has weighty diagonal elements close to one. In this paper, the authors investigate the effects of using the Grassmann-Taksar-Heyman (GTH) method to solve the coupling matrix formed in the aggregation step. Then, they extend the idea in such a way that this direct method can be incorporated into the disaggregation step. Finally, they discuss various implementation issues, demonstrate the effect of using the GTH method in the IAD algorithm on various examples, and elaborate on the conditions under which it should be applied.

  11. Twin-Screw Extruder and Pellet Accelerator Integration Developments for ITER

    SciTech Connect (OSTI)

    Meitner, Steven J; Baylor, Larry R; Combs, Stephen Kirk; Fehling, Dan T; Foust, Charles R; McGill, James M; Rasmussen, David A; Maruyama, So

    2011-01-01

    The ITER pellet injection system consisting of a twinscrew frozen hydrogen isotope extruder, coupled to a combination solenoid actuated pellet cutter and pneumatic pellet accelerator, is under development at the Oak Ridge National Laboratory. A prototype extruder has been built to produce a continuous solid deuterium extrusion and will be integrated with a secondary section, where pellets are cut, chambered, and launched with a single-stage pneumatic accelerator into the plasma through a guide tube. This integrated pellet injection system is designed to provide 5 mm fueling pellets, injected at a rate up to 10 Hz, or 3 mm edge localized mode (ELM) triggering pellets, injected at higher rates up to 20 Hz. The pellet cutter, chamber mechanism, and the solenoid operated pneumatic valve for the accelerator are optimized to provide pellet velocities between 200-300 m/s to ensure high pellet survivability while traversing the inner wall fueling guide tubes, and outer wall ELMpacing guide tubes. This paper outlines the current twin-screwextruder design, pellet accelerator design, and the integrationrequired for both fueling and ELM pacing pellets.

  12. Millimeter wave experiment of ITER equatorial EC launcher mock-up

    SciTech Connect (OSTI)

    Takahashi, K.; Oda, Y.; Kajiwara, K.; Kobayashi, N.; Isozaki, M.; Sakamoto, K.; Omori, T.; Henderson, M.

    2014-02-12

    The full-scale mock-up of the equatorial launcher was fabricated in basis of the baseline design to investigate the mm-wave propagation properties of the launcher, the manufacturability, the cooling line management, how to assemble the components and so on. The mock-up consists of one of three mm-wave transmission sets and one of eight waveguide lines can deliver the mm-wave power. The mock-up was connected to the ITER compatible transmission line and the 170GHz gyrotron and the high power experiment was carried out. The measured radiation pattern of the beam at the location of 2.5m away from the EL mock-up shows the successful steering capability of 20°∼40°. It was also revealed that the radiated profile at both steering and fixed focusing mirror agreed with the calculation. The result also suggests that some unwanted modes are included in the radiated beam. Transmission of 0.5MW-0.4sec and of 0.12MW-50sec were also demonstrated.

  13. High resolution fast wave reflectometry: JET design and implications for ITER

    SciTech Connect (OSTI)

    Cupido, L.; Igreja, R.; Serra, F.; Manso, M. E.; Cardinali, A.; Murari, A.

    2008-10-15

    The measurement of the fuel mixture remains a very difficult task in thermonuclear plasmas, where the hydrogen isotopes are fully stripped and do not emit line radiation. On the other hand, direct determination of the ion species mix will be essential in the reactor to keep the mixture close to 50/50 and maximize the fusion output. In this paper, the design of fast wave reflectometry for JET is reviewed to show the potential of such a method in the perspective of ITER. The main design elements of the antenna and the detection system, based on vectorial measurements, are reported. The main challenges to such a diagnostic, mainly the intrinsic ion cyclotron emission from the plasma and the extensive use of ion cyclotron radiofrequencies as additional heating, are addressed in detail. The overall design indicates that the proposed system would be able to provide a measurement of the fuel ratio with spatial resolution in the range of few centimeters and temporal resolution in the range of 1 ms in the vast majority of JET scenarios.

  14. Iterative optimizing quantization method for reconstructing three-dimensional images from a limited number of views

    DOE Patents [OSTI]

    Lee, Heung-Rae

    1997-01-01

    A three-dimensional image reconstruction method comprises treating the object of interest as a group of elements with a size that is determined by the resolution of the projection data, e.g., as determined by the size of each pixel. One of the projections is used as a reference projection. A fictitious object is arbitrarily defined that is constrained by such reference projection. The method modifies the known structure of the fictitious object by comparing and optimizing its four projections to those of the unknown structure of the real object and continues to iterate until the optimization is limited by the residual sum of background noise. The method is composed of several sub-processes that acquire four projections from the real data and the fictitious object: generate an arbitrary distribution to define the fictitious object, optimize the four projections, generate a new distribution for the fictitious object, and enhance the reconstructed image. The sub-process for the acquisition of the four projections from the input real data is simply the function of acquiring the four projections from the data of the transmitted intensity. The transmitted intensity represents the density distribution, that is, the distribution of absorption coefficients through the object.

  15. Iterative optimizing quantization method for reconstructing three-dimensional images from a limited number of views

    DOE Patents [OSTI]

    Lee, H.R.

    1997-11-18

    A three-dimensional image reconstruction method comprises treating the object of interest as a group of elements with a size that is determined by the resolution of the projection data, e.g., as determined by the size of each pixel. One of the projections is used as a reference projection. A fictitious object is arbitrarily defined that is constrained by such reference projection. The method modifies the known structure of the fictitious object by comparing and optimizing its four projections to those of the unknown structure of the real object and continues to iterate until the optimization is limited by the residual sum of background noise. The method is composed of several sub-processes that acquire four projections from the real data and the fictitious object: generate an arbitrary distribution to define the fictitious object, optimize the four projections, generate a new distribution for the fictitious object, and enhance the reconstructed image. The sub-process for the acquisition of the four projections from the input real data is simply the function of acquiring the four projections from the data of the transmitted intensity. The transmitted intensity represents the density distribution, that is, the distribution of absorption coefficients through the object. 5 figs.

  16. Magnetostatic focal spot correction for x-ray tubes operating in strong magnetic fields using iterative optimization

    SciTech Connect (OSTI)

    Lillaney, Prasheel; Shin, Mihye; Conolly, Steven M.; Fahrig, Rebecca

    2012-09-15

    Purpose: Combining x-ray fluoroscopy and MR imaging systems for guidance of interventional procedures has become more commonplace. By designing an x-ray tube that is immune to the magnetic fields outside of the MR bore, the two systems can be placed in close proximity to each other. A major obstacle to robust x-ray tube design is correcting for the effects of the magnetic fields on the x-ray tube focal spot. A potential solution is to design active shielding that locally cancels the magnetic fields near the focal spot. Methods: An iterative optimization algorithm is implemented to design resistive active shielding coils that will be placed outside the x-ray tube insert. The optimization procedure attempts to minimize the power consumption of the shielding coils while satisfying magnetic field homogeneity constraints. The algorithm is composed of a linear programming step and a nonlinear programming step that are interleaved with each other. The coil results are verified using a finite element space charge simulation of the electron beam inside the x-ray tube. To alleviate heating concerns an optimized coil solution is derived that includes a neodymium permanent magnet. Any demagnetization of the permanent magnet is calculated prior to solving for the optimized coils. The temperature dynamics of the coil solutions are calculated using a lumped parameter model, which is used to estimate operation times of the coils before temperature failure. Results: For a magnetic field strength of 88 mT, the algorithm solves for coils that consume 588 A/cm{sup 2}. This specific coil geometry can operate for 15 min continuously before reaching temperature failure. By including a neodymium magnet in the design the current density drops to 337 A/cm{sup 2}, which increases the operation time to 59 min. Space charge simulations verify that the coil designs are effective, but for oblique x-ray tube geometries there is still distortion of the focal spot shape along with deflections of

  17. Manager`s views of public involvement

    SciTech Connect (OSTI)

    Branch, K.M.; Heerwagen, J.; Bradbury, J.

    1995-12-01

    Four issues commonly form the framework for debates about the acceptability of proposed projects or technologies--the substantive decision or technological choice; the treatment of the community by the proponent organization; the way the decision-making process has been structured and managed; and the status of institutional safeguards and protection. One of the clear messages of cultural theory is that differences in perspectives are a normal and inevitable part of society, and that attempts to resolve differences by persuasion are not likely to work. These findings are useful when considering the goals and possibilities of public involvement as a decision-making tool, and when designing or evaluating public involvement training programs for managers. The research reported here examines the viewpoints and concerns of managers and decision-makers about the four issues identified above, with particular emphasis on their perspectives and concerns about opening decision-making processes to the public and about managers` roles and responsibilities for structuring and managing open decision-making processes. Implications of these findings for public involvement training for managers is also discussed. The data presented in this paper were obtained from face-to-face interviews with managers and decision-makers with experience managing a variety of hazardous waste management decision-making processes. We conducted these interviews in the course of four separate research projects: needs assessments to support the design and development of a public involvement training program for managers; a study of community residents` and managers` perspectives on the chemical stockpile disposal program; an evaluation of the effectiveness of public involvement training for managers in the Department of Energy; and a study to develop indicators of the benefits and costs of public involvement.

  18. Modeling

    SciTech Connect (OSTI)

    Loth, E.; Tryggvason, G.; Tsuji, Y.; Elghobashi, S. E.; Crowe, Clayton T.; Berlemont, A.; Reeks, M.; Simonin, O.; Frank, Th; Onishi, Yasuo; Van Wachem, B.

    2005-09-01

    Slurry flows occur in many circumstances, including chemical manufacturing processes, pipeline transfer of coal, sand, and minerals; mud flows; and disposal of dredged materials. In this section we discuss slurry flow applications related to radioactive waste management. The Hanford tank waste solids and interstitial liquids will be mixed to form a slurry so it can be pumped out for retrieval and treatment. The waste is very complex chemically and physically. The ARIEL code is used to model the chemical interactions and fluid dynamics of the waste.

  19. PCG: A software package for the iterative solution of linear systems on scalar, vector and parallel computers

    SciTech Connect (OSTI)

    Joubert, W.; Carey, G.F.

    1994-12-31

    A great need exists for high performance numerical software libraries transportable across parallel machines. This talk concerns the PCG package, which solves systems of linear equations by iterative methods on parallel computers. The features of the package are discussed, as well as techniques used to obtain high performance as well as transportability across architectures. Representative numerical results are presented for several machines including the Connection Machine CM-5, Intel Paragon and Cray T3D parallel computers.

  20. Resources for global risk assessment: The International Toxicity Estimates for Risk (ITER) and Risk Information Exchange (RiskIE) databases

    SciTech Connect (OSTI)

    Wullenweber, Andrea Kroner, Oliver; Kohrman, Melissa; Maier, Andrew; Dourson, Michael; Rak, Andrew; Wexler, Philip; Tomljanovic, Chuck

    2008-11-15

    The rate of chemical synthesis and use has outpaced the development of risk values and the resolution of risk assessment methodology questions. In addition, available risk values derived by different organizations may vary due to scientific judgments, mission of the organization, or use of more recently published data. Further, each organization derives values for a unique chemical list so it can be challenging to locate data on a given chemical. Two Internet resources are available to address these issues. First, the International Toxicity Estimates for Risk (ITER) database ( (www.tera.org/iter)) provides chronic human health risk assessment data from a variety of organizations worldwide in a side-by-side format, explains differences in risk values derived by different organizations, and links directly to each organization's website for more detailed information. It is also the only database that includes risk information from independent parties whose risk values have undergone independent peer review. Second, the Risk Information Exchange (RiskIE) is a database of in progress chemical risk assessment work, and includes non-chemical information related to human health risk assessment, such as training modules, white papers and risk documents. RiskIE is available at (http://www.allianceforrisk.org/RiskIE.htm), and will join ITER on National Library of Medicine's TOXNET ( (http://toxnet.nlm.nih.gov/)). Together, ITER and RiskIE provide risk assessors essential tools for easily identifying and comparing available risk data, for sharing in progress assessments, and for enhancing interaction among risk assessment groups to decrease duplication of effort and to harmonize risk assessment procedures across organizations.

  1. Public Involvement and Communications Committee Page 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    June 1, 2011 FINAL MEETING SUMMARY HANFORD ADVISORY BOARD PUBLIC INVOLVEMENT & COMMUNICATIONS COMMITTEE MEETING June 1, 2011 Kennewick, WA Topics in this Meeting Summary Welcome and Introductions .......................................................................................................................... 1 Comprehensive Debrief - State of the Site Meetings ................................................................................... 4 Public Meetings - PW-1/3/6 and CW-5

  2. Modelling of edge localised modes and edge localised mode control

    SciTech Connect (OSTI)

    Huijsmans, G. T. A.; Loarte, A.; Chang, C. S.; Ferraro, N.; Sugiyama, L.; Waelbroeck, F.; Xu, X. Q.; Futatani, S.

    2015-02-15

    Edge Localised Modes (ELMs) in ITER Q = 10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. To avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field perturbations created by in-vessel coils and the injection of small D2 pellets. ITER plasmas are characterised by low collisionality at a high density (high fraction of the Greenwald density limit). These parameters cannot simultaneously be achieved in current experiments. Therefore, the extrapolation of the ELM properties and the requirements for ELM control in ITER relies on the development of validated physics models and numerical simulations. In this paper, we describe the modelling of ELMs and ELM control methods in ITER. The aim of this paper is not a complete review on the subject of ELM and ELM control modelling but rather to describe the current status and discuss open issues.

  3. WE-G-18A-03: Cone Artifacts Correction in Iterative Cone Beam CT Reconstruction

    SciTech Connect (OSTI)

    Yan, H; Folkerts, M; Jiang, S; Jia, X; Wang, X; Bai, T; Lu, W

    2014-06-15

    Purpose: For iterative reconstruction (IR) in cone-beam CT (CBCT) imaging, data truncation along the superior-inferior (SI) direction causes severe cone artifacts in the reconstructed CBCT volume images. Not only does it reduce the effective SI coverage of the reconstructed volume, it also hinders the IR algorithm convergence. This is particular a problem for regularization based IR, where smoothing type regularization operations tend to propagate the artifacts to a large area. It is our purpose to develop a practical cone artifacts correction solution. Methods: We found it is the missing data residing in the truncated cone area that leads to inconsistency between the calculated forward projections and measured projections. We overcome this problem by using FDK type reconstruction to estimate the missing data and design weighting factors to compensate the inconsistency caused by the missing data. We validate the proposed methods in our multi-GPU low-dose CBCT reconstruction system on multiple patients' datasets. Results: Compared to the FDK reconstruction with full datasets, while IR is able to reconstruct CBCT images using a subset of projection data, the severe cone artifacts degrade overall image quality. For head-neck case under a full-fan mode, 13 out of 80 slices are contaminated. It is even more severe in pelvis case under half-fan mode, where 36 out of 80 slices are affected, leading to inferior soft-tissue delineation. By applying the proposed method, the cone artifacts are effectively corrected, with a mean intensity difference decreased from ∼497 HU to ∼39HU for those contaminated slices. Conclusion: A practical and effective solution for cone artifacts correction is proposed and validated in CBCT IR algorithm. This study is supported in part by NIH (1R01CA154747-01)

  4. Resolution enhancement of lung 4D-CT data using multiscale interphase iterative nonlocal means

    SciTech Connect (OSTI)

    Zhang Yu; Yap, Pew-Thian; Wu Guorong; Feng Qianjin; Chen Wufan; Lian Jun; Shen Dinggang

    2013-05-15

    Purpose: Four-dimensional computer tomography (4D-CT) has been widely used in lung cancer radiotherapy due to its capability in providing important tumor motion information. However, the prolonged scanning duration required by 4D-CT causes considerable increase in radiation dose. To minimize the radiation-related health risk, radiation dose is often reduced at the expense of interslice spatial resolution. However, inadequate resolution in 4D-CT causes artifacts and increases uncertainty in tumor localization, which eventually results in extra damages of healthy tissues during radiotherapy. In this paper, the authors propose a novel postprocessing algorithm to enhance the resolution of lung 4D-CT data. Methods: The authors' premise is that anatomical information missing in one phase can be recovered from the complementary information embedded in other phases. The authors employ a patch-based mechanism to propagate information across phases for the reconstruction of intermediate slices in the longitudinal direction, where resolution is normally the lowest. Specifically, the structurally matching and spatially nearby patches are combined for reconstruction of each patch. For greater sensitivity to anatomical details, the authors employ a quad-tree technique to adaptively partition the image for more fine-grained refinement. The authors further devise an iterative strategy for significant enhancement of anatomical details. Results: The authors evaluated their algorithm using a publicly available lung data that consist of 10 4D-CT cases. The authors' algorithm gives very promising results with significantly enhanced image structures and much less artifacts. Quantitative analysis shows that the authors' algorithm increases peak signal-to-noise ratio by 3-4 dB and the structural similarity index by 3%-5% when compared with the standard interpolation-based algorithms. Conclusions: The authors have developed a new algorithm to improve the resolution of 4D-CT. It outperforms

  5. Thermo-structural development of the ITER ICRF strap housing module

    SciTech Connect (OSTI)

    Winkler, K.; Shannon, M.; Lockley, D.

    2014-02-12

    Since March 2010 the preliminary design of the ITER ICRF Antennas have been developed by CYCLE, a consortium consisting of IPP (Garching), CCFE (Culham), CEA (Cadarache), Politecnico di Torino (Torino) and LPPERM/KMS (Brussels). This paper describes the steps taken to develop the present geometry of the triplet pair Strap Housing Module from a thermal and structural perspective, and shows the critical areas of the structure. Key issues are the manufacturability, (achieved by HIPing - Hot Isostatic Pressing), the ability to handle the radiating plasma thermal flux of 0.35 MW/m{sup 2}, the RF losses and the neutronic radiation. HIPing is necessary to achieve the complicated system of cooling channels inside the structure, which divides the coolant equally in order to supply each strap in the triplet with 1 l/s of water. The components have also to withstand the strong mechanical forces generated by plasma disruptions affecting all internal structures and the elevated design cooling water pressure of 5MPa. In order to maximise reliability, joints between different materials in the cooling water system have been kept to a minimum. Therefore, in the interests of fabricability and availability, the whole structure is manufactured out of stainless steel (316L(N)IG). The low conductivity of 316L(N)IG demands small wall thicknesses to avoid hot spots; however this reduces the mechanical strength. Consequently an in depth FEM analysis is presented, which was used to find and to improve the critical aspects of this important component and was the best means of finding the optimum between thermal and mechanical performance.

  6. Powerloads on the front end components and the duct of the heating and diagnostic neutral beam lines at ITER

    SciTech Connect (OSTI)

    Singh, M. J.; Boilson, D.; Hemsworth, R. S.; Geli, F.; Graceffa, J.; Urbani, M.; Schunke, B.; Chareyre, J.; Dlougach, E.; Krylov, A.

    2015-04-08

    The heating and current drive beam lines (HNB) at ITER are expected to deliver ∼16.7 MW power per beam line for H beams at 870 keV and D beams at 1 MeV during the H-He and the DD/DT phases of ITER operation respectively. On the other hand the diagnostic neutral beam (DNB) line shall deliver ∼2 MW power for H beams at 100 keV during both the phases. The path lengths over which the beams from the HNB and DNB beam lines need to be transported are 25.6 m and 20.7 m respectively. The transport of the beams over these path lengths results in beam losses, mainly by the direct interception of the beam with the beam line components and reionisation. The lost power is deposited on the surfaces of the various components of the beam line. In order to ensure the survival of these components over the operational life time of ITER, it is important to determine to the best possible extent the operational power loads and power densities on the various surfaces which are impacted by the beam in one way or the other during its transport. The main factors contributing to these are the divergence of the beamlets and the halo fraction in the beam, the beam aiming, the horizontal and vertical misalignment of the beam, and the gas profile along the beam path, which determines the re-ionisation loss, and the re-ionisation cross sections. The estimations have been made using a combination of the modified version of the Monte Carlo Gas Flow code (MCGF) and the BTR code. The MCGF is used to determine the gas profile in the beam line and takes into account the active gas feed into the ion source and neutraliser, the HNB-DNB cross over, the gas entering the beamline from the ITER machine, the additional gas atoms generated in the beam line due to impacting ions and the pumping speed of the cryopumps. The BTR code has been used to obtain the power loads and the power densities on the various surfaces of the front end components and the duct modules for different scenarios of ITER

  7. Sandia National Laboratories: Community Involvement: Volunteer Programs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Community Involvement Contribution Programs Volunteer Programs Education Programs About Volunteer Programs Helping where we are needed Habitat for Humanity Employees and retirees are passionate about volunteering. You'll find Sandians judging science fairs, coaching sports teams, leading scouting troops, sorting food, building houses, and serving on community boards. In support of individual volunteer efforts, Sandia provides a volunteer website to advertise current volunteer opportunities and

  8. Sandia National Laboratories: About Sandia: Community Involvement:

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Education Programs: Science, Technology, Engineering and Math Programs Science, Technology, Engineering, and Math Programs Future scientists photo Our science, technology, engineering, and math (STEM) programs engage students by linking science to the real world. We offer three unique programs for American Indian students, African American students, and Hispanic students. The programs get students involved in fun, hands-on science and engineering activities and provide an opportunity to

  9. Evaluation of inter-laminar shear strength of GFRP composed of bonded glass/polyimide tapes and cyanate-ester/epoxy blended resin for ITER TF coils

    SciTech Connect (OSTI)

    Hemmi, T.; Matsui, K.; Koizumi, N.; Nishimura, A.; Nishijima, S.; Shikama, T.

    2014-01-27

    The insulation system of the ITER TF coils consists of multi-layer glass/polyimide tapes impregnated a cyanate-ester/epoxy resin. The ITER TF coils are required to withstand an irradiation of 10 MGy from gamma-ray and neutrons since the ITER TF coils is exposed by fast neutron (>0.1 MeV) of 10{sup 22} n/m{sup 2} during the ITER operation. Cyanate-ester/epoxy blended resins and bonded glass/polyimide tapes are developed as insulation materials to realize the required radiation-hardness for the insulation of the ITER TF coils. To evaluate the radiation-hardness of the developed insulation materials, the inter-laminar shear strength (ILSS) of glass-fiber reinforced plastics (GFRP) fabricated using developed insulation materials is measured as one of most important mechanical properties before/after the irradiation in a fission reactor of JRR-3M. As a result, it is demonstrated that the GFRPs using the developed insulation materials have a sufficient performance to apply for the ITER TF coil insulation.

  10. IDC Re-Engineering Phase 2 Iteration E1 Use Cases.

    SciTech Connect (OSTI)

    Harris, James M.; Carr, Dorthe B.; Coram, Jamie L.

    2016-01-01

    This document contains 21 use cases generated from the model contained in Rational Software Architect.

  11. Characterization of a constrained paired-view technique in iterative reconstruction for breast tomosynthesis

    SciTech Connect (OSTI)

    Wu, Gang; Yaffe, Martin J.; Mainprize, James G.

    2013-10-15

    Purpose: The order in which the projection views are employed in the reconstruction of tomosynthesis by iterative algorithms, such as simultaneous algebraic reconstruction technique and maximum likelihood, has a strong effect on the rate of convergence, accuracy, and the edge-blurring artifacts in the reconstructed image. The purpose of this investigation was to characterize and evaluate the effects of ordering schemes on image quality for breast tomosynthesis reconstruction and to explore a new constrained paired-view technique that could provide reduction of reconstruction artifacts. In this work, the authors compared several different ordering schemes and characterized the image quality and the formation of out-of-plane artifacts. Furthermore, a new normalization method is presented. It produces more accurate reconstructions with reduced artifacts comparing to the standard method of sequential ordering.Methods: In addition to visual assessment of image quality, several indices such as the signal-difference-to-noise ratio, the artifact-spread function, and the lesion detectability (d{sup ?}) were computed to quantitatively evaluate the effect of ordering scheme. The sets of breast tomosynthesis projection images were simulated for reconstruction; one set had uniform background (white noise only) and the other two contained both anatomic background and quantum noise. Clinical breast images were also studied for comparison.Results: The authors have quantified the image quality in reconstructed slices for a range of tumor sizes. The authors proposed method provides better performance for all of the metrics tested (contrast, d{sup ?}, and the level of artifacts) both for the uniform phantom case and in the presence of anatomical structure.Conclusions: The paired projection normalization provides better performance in the image quality of the reconstructed slices, and results in a lower level of artifacts in the Z direction. This implies that even a relatively simple

  12. SU-F-18C-06: Prospective Patient Evaluation of Iterative Reconstruction in Radiation Oncology

    SciTech Connect (OSTI)

    Price, R; Vance, S; Cattaneo, R; Schultz, L; Elshaikh, M; Chetty, I; Glide-Hurst, C

    2014-06-15

    Purpose: This work incorporates iterative reconstruction (IR) into a dose reduction study to characterize image quality metrics, delineation, and dosimetric assessment, with the goal of reducing imaging dose in Radiation Oncology. Methods: Three-dimensional noise power spectrum (NPS) analysis characterized noise magnitude/texture (120 kVp, 50–200 mAs, IR levels 1–6 yielding noise reduction of 0.89–0.55 compared to filtered backprojection (FBP)). Task-specific Modulation Transfer Functions (MTFtask) were characterized across varied subject contrasts. A prospective dose reduction study (500 to 150 mAs) was conducted for 12 patients (43 inter-fraction CTs) for high-dose rate brachytherapy. Three physicians performed qualitative image assessment between full-dose FBP (FD-FBP, 500 mAs), low-dose FBP (LD-FBP, 150–250 mAs), and low-dose IRL5-6 (LD-IR) scans for image noise, cuff/bladder interface detectability, spatial resolution, texture, and segmentation confidence. Comparisons between LD-FBP and LD-IR were conducted for the following metrics: delineation (bladder and rectum evaluated via overlap indices (OI) and Dice similarity coefficients (DSC)), noise, boundary changes, dose calculation, and digitally reconstructed radiographs (DRRs). Results: NPS showed ∼50% reduction in noise magnitude and ∼0.1 1/mm spatial frequency shift with IRL6. The largest MTFtask decrease between FBP and IR was 0.08 A.U. Qualitative patient image evaluation revealed LD-IR was equivalent or slightly worse than FD-FBP, and superior to LD-FBP for all metrics except low contrast interface and texture. The largest CT number discrepancy from FBP occurred at a bone/tissue interface using IRL6 (−1.2 ± 4.9 HU (range: −17.6 – 12.5 HU)). No significant contour differences (OIs and DSCs = 0.85 – 0.95) and dose calculation discrepancy (<0.02%) were observed. DRRs preserved anatomical detail and demonstrated <2% difference in intensity between LD-FBP and LD-IRL6. Conclusion: While

  13. Failure analysis of beryllium tile assembles following high heat flux testing for the ITER program

    SciTech Connect (OSTI)

    B. C. Odegard, Jr.; C. H. Cadden; N. Y. C. Yang

    2000-05-01

    The following document describes the processing, testing and post-test analysis of two Be-Cu assemblies that have successfully met the heat load requirements for the first wall and dome sections for the ITER (International Thermonuclear Experimental Reactor) fusion reactor. Several different joint assemblies were evaluated in support of a manufacturing technology investigation aimed at diffusion bonding or brazing a beryllium armor tile to a copper alloy heat sink for fusion reactor applications. Judicious selection of materials and coatings for these assemblies was essential to eliminate or minimize interactions with the highly reactive beryllium armor material. A thin titanium layer was used as a diffusion barrier to isolate the copper heat sink from the beryllium armor. To reduce residual stresses produced by differences in the expansion coefficients between the beryllium and copper, a compliant layer of aluminum or aluminum-beryllium (AlBeMet-150) was used. Aluminum was chosen because it does not chemically react with, and exhibits limited volubility in, beryllium. Two bonding processes were used to produce the assemblies. The primary process was a diffusion bonding technique. In this case, undesirable metallurgical reactions were minimized by keeping the materials in a solid state throughout the fabrication cycle. The other process employed an aluminum-silicon layer as a brazing filler material. In both cases, a hot isostatic press (HIP) furnace was used in conjunction with vacuum-canned assemblies in order to minimize oxidation and provide sufficient pressure on the assemblies for full metal-to-metal contact and subsequent bonding. The two final assemblies were subjected to a suite of tests including: tensile tests and electron and optical metallography. Finally, high heat flux testing was conducted at the electron beam testing system (EBTS) at Sandia National Laboratories, New Mexico. Here, test mockups were fabricated and subjected to normal heat loads to

  14. World Energy Projection System Plus Model Documentation: Commercial Model

    Reports and Publications (EIA)

    2016-01-01

    The Commercial Model of the World Energy Projection System Plus (WEPS ) is an energy demand modeling system of the world commercial end?use sector at a regional level. This report describes the version of the Commercial Model that was used to produce the commercial sector projections published in the International Energy Outlook 2016 (IEO2016). The Commercial Model is one of 13 components of the WEPS system. The WEPS is a modular system, consisting of a number of separate energy models that are communicate and work with each other through an integrated system model. The model components are each developed independently, but are designed with well?defined protocols for system communication and interactivity. The WEPS modeling system uses a shared database (the “restart” file) that allows all the models to communicate with each other when they are run in sequence over a number of iterations. The overall WEPS system uses an iterative solution technique that forces convergence of consumption and supply pressures to solve for an equilibrium price.

  15. Combined iterative reconstruction and image-domain decomposition for dual energy CT using total-variation regularization

    SciTech Connect (OSTI)

    Dong, Xue; Niu, Tianye; Zhu, Lei

    2014-05-15

    Purpose: Dual-energy CT (DECT) is being increasingly used for its capability of material decomposition and energy-selective imaging. A generic problem of DECT, however, is that the decomposition process is unstable in the sense that the relative magnitude of decomposed signals is reduced due to signal cancellation while the image noise is accumulating from the two CT images of independent scans. Direct image decomposition, therefore, leads to severe degradation of signal-to-noise ratio on the resultant images. Existing noise suppression techniques are typically implemented in DECT with the procedures of reconstruction and decomposition performed independently, which do not explore the statistical properties of decomposed images during the reconstruction for noise reduction. In this work, the authors propose an iterative approach that combines the reconstruction and the signal decomposition procedures to minimize the DECT image noise without noticeable loss of resolution. Methods: The proposed algorithm is formulated as an optimization problem, which balances the data fidelity and total variation of decomposed images in one framework, and the decomposition step is carried out iteratively together with reconstruction. The noise in the CT images from the proposed algorithm becomes well correlated even though the noise of the raw projections is independent on the two CT scans. Due to this feature, the proposed algorithm avoids noise accumulation during the decomposition process. The authors evaluate the method performance on noise suppression and spatial resolution using phantom studies and compare the algorithm with conventional denoising approaches as well as combined iterative reconstruction methods with different forms of regularization. Results: On the Catphan600 phantom, the proposed method outperforms the existing denoising methods on preserving spatial resolution at the same level of noise suppression, i.e., a reduction of noise standard deviation by one order

  16. Free Legal Services - Attracting Legal Talent for Public Involvement Groups

    SciTech Connect (OSTI)

    Domby, A.H.

    2007-07-01

    This paper reviews the public service responsibilities of lawyers, and how they can fulfill the annual goal of performing pro bono services by serving certain public involvement groups, including organization involved in Constitutional issues and environmental protection matters. Public involvement groups should consider their needs for legal services and consider soliciting lawyers to serve on their boards or to volunteer legal services which will assist those lawyers in fulfilling their professional obligations under Rules of Professional Conduct. The group should identify specific activities and tasks that require the skills and training of a lawyer, including corporate governance issues; conflict-of-interest questions; the statutory construction of laws, regulations and ordinances; or analysis of potential liability. The addition of a lawyer to advisory boards for governmental agencies and for non-profit boards of charitable, religious, civic, community, environmental and educational organizations may provide those boards with knowledge, analytical approaches and insights that complement the abilities of other board members. Rules of Professional Conduct applicable to lawyers include admonitions for lawyers to provide 'Public Service'. Representative of many rules, the American Bar Association Model Rule 6.1, entitled 'Voluntary Pro Bono Publico Service' addresses every lawyer's professional responsibility to provide legal services to those 'unable to pay'. This Model Rule exhorts each lawyer to provide fifty (50) hours of legal services without fee or expectation of fee to persons of limited means or charitable, religious or civic, community, governmental and educational organizations or to individuals, groups or organizations seeking 'to secure or protect civil rights, civil liberties, or public rights, or charitable, religious, civic, community, governmental and educational organizations in matters in furtherance of their purposes, where the payment of

  17. Apolipoprotein gene involved in lipid metabolism

    DOE Patents [OSTI]

    Rubin, Edward; Pennacchio, Len A.

    2007-07-03

    Methods and materials for studying the effects of a newly identified human gene, APOAV, and the corresponding mouse gene apoAV. The sequences of the genes are given, and transgenic animals which either contain the gene or have the endogenous gene knocked out are described. In addition, single nucleotide polymorphisms (SNPs) in the gene are described and characterized. It is demonstrated that certain SNPs are associated with diseases involving lipids and triglycerides and other metabolic diseases. These SNPs may be used alone or with SNPs from other genes to study individual risk factors. Methods for intervention in lipid diseases, including the screening of drugs to treat lipid-related or diabetic diseases are also disclosed.

  18. Clinical evaluation of the iterative metal artifact reduction algorithm for CT simulation in radiotherapy

    SciTech Connect (OSTI)

    Axente, Marian; Von Eyben, Rie; Hristov, Dimitre; Paidi, Ajay; Bani-Hashemi, Ali; Zeng, Chuan; Krauss, Andreas

    2015-03-15

    Purpose: To clinically evaluate an iterative metal artifact reduction (IMAR) algorithm prototype in the radiation oncology clinic setting by testing for accuracy in CT number retrieval, relative dosimetric changes in regions affected by artifacts, and improvements in anatomical and shape conspicuity of corrected images. Methods: A phantom with known material inserts was scanned in the presence/absence of metal with different configurations of placement and sizes. The relative change in CT numbers from the reference data (CT with no metal) was analyzed. The CT studies were also used for dosimetric tests where dose distributions from both photon and proton beams were calculated. Dose differences and gamma analysis were calculated to quantify the relative changes between doses calculated on the different CT studies. Data from eight patients (all different treatment sites) were also used to quantify the differences between dose distributions before and after correction with IMAR, with no reference standard. A ranking experiment was also conducted to analyze the relative confidence of physicians delineating anatomy in the near vicinity of the metal implants. Results: IMAR corrected images proved to accurately retrieve CT numbers in the phantom study, independent of metal insert configuration, size of the metal, and acquisition energy. For plastic water, the mean difference between corrected images and reference images was −1.3 HU across all scenarios (N = 37) with a 90% confidence interval of [−2.4, −0.2] HU. While deviations were relatively higher in images with more metal content, IMAR was able to effectively correct the CT numbers independent of the quantity of metal. Residual errors in the CT numbers as well as some induced by the correction algorithm were found in the IMAR corrected images. However, the dose distributions calculated on IMAR corrected images were closer to the reference data in phantom studies. Relative spatial difference in the dose

  19. Enhanced Confinement Scenarios Without Large Edge Localized Modes in Tokamaks: Control, Performance, and Extrapolability Issues for ITER

    SciTech Connect (OSTI)

    Maingi, R

    2014-07-01

    Large edge localized modes (ELMs) typically accompany good H-mode confinement in fusion devices, but can present problems for plasma facing components because of high transient heat loads. Here the range of techniques for ELM control deployed in fusion devices is reviewed. The two baseline strategies in the ITER baseline design are emphasized: rapid ELM triggering and peak heat flux control via pellet injection, and the use of magnetic perturbations to suppress or mitigate ELMs. While both of these techniques are moderately well developed, with reasonable physical bases for projecting to ITER, differing observations between multiple devices are also discussed to highlight the needed community R & D. In addition, recent progress in ELM-free regimes, namely Quiescent H-mode, I-mode, and Enhanced Pedestal H-mode is reviewed, and open questions for extrapolability are discussed. Finally progress and outstanding issues in alternate ELM control techniques are reviewed: supersonic molecular beam injection, edge electron cyclotron heating, lower hybrid heating and/or current drive, controlled periodic jogs of the vertical centroid position, ELM pace-making via periodic magnetic perturbations, ELM elimination with lithium wall conditioning, and naturally occurring small ELM regimes.

  20. Erosion products of plasma facing materials formed under ITER-like transient load and deuterium retention in them

    SciTech Connect (OSTI)

    Putrik, A. B. Klimov, N. S.; Gasparyan, Yu. M. Efimov, V. S.; Barsuk, V. A.; Podkovyrov, V. L. Zhitlukhin, A. M. Yarochevskaya, A. D.; Kovalenko, D. V.

    2015-12-15

    Erosion of the plasma-facing materials in particular evaporation of the materials in a fusion reactor under intense transient events is one of the problems of the ITER. The current experimental data are insufficient to predict the properties of the erosion products, a significant part of which will be formed during transient events (edge-localized modes (ELMs) and disruptions). The paper concerns the experimental investigation of the graphite and tungsten erosion products deposited under pulsed plasma load at the QSPA-T: heat load on the target was 2.6 MJ/m{sup 2} with 0.5 ms pulse duration. The designed diagnostics for measuring the deposition rate made it possible to determine that the deposition of eroded material occurs during discharge, and the deposition rate is in the range (0.1–100) × 10{sup 19} at/(cm{sup 2} s), which is much higher than that for stationary processes. It is found that the relative atomic concentrations D/C and D/(W + C) in the erosion products deposited during the pulse process are on the same level as for the stationary processes. An exposure of erosion products to photonic energy densities typical of those expected at mitigated disruptions in the ITER (pulse duration of 0.5–1 ms, integral energy density of radiation of 0.1–0.5 MJ/m2) significantly decreases the concentration of trapped deuterium.

  1. Development of a laser cleaning method for the first mirror surface of the charge exchange recombination spectroscopy diagnostics on ITER

    SciTech Connect (OSTI)

    Kuznetsov, A. P.; Buzinskij, O. I.; Gubsky, K. L.; Nikitina, E. A.; Savchenkov, A. V.; Tarasov, B. A.; Tugarinov, S. N.

    2015-12-15

    A set of optical diagnostics is expected for measuring the plasma characteristics in ITER. Optical elements located inside discharge chambers are exposed to an intense radiation load, sputtering due to collisions with energetic atoms formed in the charge transfer processes, and contamination due to recondensation of materials sputtered from different parts of the construction of the chamber. Removing the films of the sputtered materials from the mirrors with the aid of pulsed laser radiation is an efficient cleaning method enabling recovery of the optical properties of the mirrors. In this work, we studied the efficiency of removal of metal oxide films by pulsed radiation of a fiber laser. Optimization of the laser cleaning conditions was carried out on samples representing metal substrates polished with optical quality with deposition of films on them imitating the chemical composition and conditions expected in ITER. It is shown that, by a proper selection of modes of radiation exposure to the surface with a deposited film, it is feasible to restore the original high reflection characteristics of optical elements.

  2. Long pulse acceleration of MeV class high power density negative H{sup −} ion beam for ITER

    SciTech Connect (OSTI)

    Umeda, N. Kojima, A.; Kashiwagi, M.; Tobari, H.; Hiratsuka, J.; Watanabe, K.; Dairaku, M.; Yamanaka, H.; Hanada, M.

    2015-04-08

    R and D of high power density negative ion beam acceleration has been carried out at MeV test facility in JAEA to realize ITER neutral beam accelerator. The main target is H{sup −} ion beam acceleration up to 1 MeV with 200 A/m{sup 2} for 60 s whose pulse length is the present facility limit. For long pulse acceleration at high power density, new extraction grid (EXG) has been developed with high cooling capability, which electron suppression magnet is placed under cooling channel similar to ITER. In addition, aperture size of electron suppression grid (ESG) is enlarged from 14 mm to 16 mm to reduce direct interception on the ESG and emission of secondary electron which leads to high heat load on the upstream acceleration grid. By enlarging ESG aperture, beam current increased 10 % at high current beam and total acceleration grid heat load reduced from 13 % to 10 % of input power at long pulse beam. In addition, heat load by back stream positive ion into the EXG is measured for the first time and is estimated as 0.3 % of beam power, while heat load by back stream ion into the source chamber is estimated as 3.5 ~ 4.0 % of beam power. Beam acceleration up to 60 s which is the facility limit, has achieved at 683 keV, 100 A/m{sup 2} of negative ion beam, whose energy density increases two orders of magnitude since 2011.

  3. Genomic Aspects of Research Involving Polyploid Plants

    SciTech Connect (OSTI)

    Yang, Xiaohan [ORNL; Ye, Chuyu [ORNL; Tschaplinski, Timothy J [ORNL; Wullschleger, Stan D [ORNL; Tuskan, Gerald A [ORNL

    2011-01-01

    Almost all extant plant species have spontaneously doubled their genomes at least once in their evolutionary histories, resulting in polyploidy which provided a rich genomic resource for evolutionary processes. Moreover, superior polyploid clones have been created during the process of crop domestication. Polyploid plants generated by evolutionary processes and/or crop domestication have been the intentional or serendipitous focus of research dealing with the dynamics and consequences of genome evolution. One of the new trends in genomics research is to create synthetic polyploid plants which provide materials for studying the initial genomic changes/responses immediately after polyploid formation. Polyploid plants are also used in functional genomics research to study gene expression in a complex genomic background. In this review, we summarize the recent progress in genomics research involving ancient, young, and synthetic polyploid plants, with a focus on genome size evolution, genomics diversity, genomic rearrangement, genetic and epigenetic changes in duplicated genes, gene discovery, and comparative genomics. Implications on plant sciences including evolution, functional genomics, and plant breeding are presented. It is anticipated that polyploids will be a regular subject of genomics research in the foreseeable future as the rapid advances in DNA sequencing technology create unprecedented opportunities for discovering and monitoring genomic and transcriptomic changes in polyploid plants. The fast accumulation of knowledge on polyploid formation, maintenance, and divergence at whole-genome and subgenome levels will not only help plant biologists understand how plants have evolved and diversified, but also assist plant breeders in designing new strategies for crop improvement.

  4. IDC Use Case Model Survey Version 1.1.

    SciTech Connect (OSTI)

    Harris, James Mark; Carr, Dorthe B.

    2015-02-01

    This document contains the brief descriptions for the actors and use cases contained in the IDC Use Case Model. REVISIONS Version Date Author/Team Revision Description Authorized by V1.0 12/2014 SNL IDC Reengineering Project Team Initial delivery M. Harris V1.1 2/2015 SNL IDC Reengineering Project Team Iteration I2 Review Comments M. Harris

  5. Observation and Modeling of Inner Divertor Re-attachment in...

    Office of Scientific and Technical Information (OSTI)

    ... and ITER Physics Expert Group on Divertor Modelling, Nucl. ... Bush, R. Kaita, H.W. Kugel, B.P. LeBlanc, S.F. Paul, G.D. ... Plasma Phys., 44:262, 2004. 5 H. A. Scott, J. Quant. ...

  6. Surface interactions involved in flashover with high density electronegative gases.

    SciTech Connect (OSTI)

    Hodge, Keith Conquest; Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Wallace, Zachariah Red; Lehr, Jane Marie

    2010-01-01

    This report examines the interactions involved with flashover along a surface in high density electronegative gases. The focus is on fast ionization processes rather than the later time ionic drift or thermalization of the discharge. A kinetic simulation of the gas and surface is used to examine electron multiplication and includes gas collision, excitation and ionization, and attachment processes, gas photoionization and surface photoemission processes, as well as surface attachment. These rates are then used in a 1.5D fluid ionization wave (streamer) model to study streamer propagation with and without the surface in air and in SF6. The 1.5D model therefore includes rates for all these processes. To get a better estimate for the behavior of the radius we have studied radial expansion of the streamer in air and in SF6. The focus of the modeling is on voltage and field level changes (with and without a surface) rather than secondary effects, such as, velocities or changes in discharge path. An experiment has been set up to carry out measurements of threshold voltages, streamer velocities, and other discharge characteristics. This setup includes both electrical and photographic diagnostics (streak and framing cameras). We have observed little change in critical field levels (where avalanche multiplication sets in) in the gas alone versus with the surface. Comparisons between model calculations and experimental measurements are in agreement with this. We have examined streamer sustaining fields (field which maintains ionization wave propagation) in the gas and on the surface. Agreement of the gas levels with available literature is good and agreement between experiment and calculation is good also. Model calculations do not indicate much difference between the gas alone versus the surface levels. Experiments have identified differences in velocity between streamers on the surface and in the gas alone (the surface values being larger).

  7. A collisional radiative model for caesium and its application to an RF source for negative hydrogen ions

    SciTech Connect (OSTI)

    Wnderlich, D. Wimmer, C.; Friedl, R.

    2015-04-08

    A collisional radiative (CR) model for caesium atoms in low-temperature, low-pressure hydrogen-caesium plasmas is introduced. This model includes the caesium ground state, 14 excited states, the singly charged caesium ion and the negative hydrogen ion. The reaction probabilities needed as input are based on data from the literature, using some scaling and extrapolations. Additionally, new cross sections for electron collision ionization and three-body recombination have been calculated. The relevance of mutual neutralization of positive caesium ions and negative hydrogen ions is highlighted: depending on the densities of the involved particle species, this excitation channel can have a significant influence on the population densities of excited states in the caesium atom. This strong influence is successfully verified by optical emission spectroscopy measurements performed at the IPP prototype negative hydrogen ion source for ITER NBI. As a consequence, population models for caesium in electronegative low-temperature, low-pressure hydrogen-caesium plasmas need to take into account the mutual neutralization process. The present CR model is an example for such models and represents an important prerequisite for deducing the total caesium density in surface production based negative hydrogen ion sources.

  8. Paducah WDA CERCLA Process & Public Involvement | Department of Energy

    Energy Savers [EERE]

    CERCLA Process & Public Involvement Paducah WDA CERCLA Process & Public Involvement The CERCLA process involves stakeholder education and input throughout the life of the project. (click graphic to enlarge) The CERCLA process involves stakeholder education and input throughout the life of the project. (click graphic to enlarge) DOE is committed to fostering meaningful community involvement in environmental remediation decision making at the site. Interactive communications enable the

  9. Phase retrieval with the transport-of-intensity equation in an arbitrarily-shaped aperture by iterative discrete cosine transforms

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, Lei; Zuo, Chao; Idir, Mourad; Qu, Weijuan; Asundi, Anand

    2015-04-21

    A novel transport-of-intensity equation (TIE) based phase retrieval method is proposed with putting an arbitrarily-shaped aperture into the optical wavefield. In this arbitrarily-shaped aperture, the TIE can be solved under non-uniform illuminations and even non-homogeneous boundary conditions by iterative discrete cosine transforms with a phase compensation mechanism. Simulation with arbitrary phase, arbitrary aperture shape, and non-uniform intensity distribution verifies the effective compensation and high accuracy of the proposed method. Experiment is also carried out to check the feasibility of the proposed method in real measurement. Comparing to the existing methods, the proposed method is applicable for any types of phasemore » distribution under non-uniform illumination and non-homogeneous boundary conditions within an arbitrarily-shaped aperture, which enables the technique of TIE with hard aperture become a more flexible phase retrieval tool in practical measurements.« less

  10. Near-field/altered-zone models report

    SciTech Connect (OSTI)

    Hardin, E. L., LLNL

    1998-03-01

    lithophysal units. These units are made up of moderately to densely welded, devitrified, fractured tuff. The rock's chemical composition is comparable to that of typical granite, but has textural features and mineralogical characteristics of large-scale, silicic volcanism. Because the repository horizon will be approximately 300 m below the ground surface and 200 m above the water table, the repository will be partially saturated. The welded tuff matrix in the host units is highly impermeable, but water and gas flow readily through fractures. The degree of fracturing in these units is highly variable, and the hydrologic significance of fracturing is an important aspect of site investigation. This report describes the characterization and modeling of a region around the potential repository--the altered zone--a region in which the temperature will be increased significantly by waste-generated heat. Numerical simulation has shown that, depending on the boundary conditions, rock properties, and repository design features incorporated in the models, the altered zone (AZ) may extend from the water table to the ground surface. This report also describes models of the near field, the region comprising the repository emplacement drifts and the surrounding rock, which are critical to the performance of engineered components. Investigations of near-field and altered-zone (NF/AZ) processes support the design of underground repository facilities and engineered barriers and also provide constraint data for probabilistic calculations of waste-isolation performance (i.e., performance assessment). The approach to investigation, which is an iterative process involving hypothesis testing and experimentation, has relied on conceptualizing engineered barriers and on performance analysis. This report is a collection, emphasizing conceptual and numerical models, of the recent results contributed from studies of NF/AZ processes and of quantitative measures of NF/AZ performance. The selection and

  11. Fusion Materials Science and Technology Research Opportunities now and during the ITER Era

    SciTech Connect (OSTI)

    Zinkle, Steven J.; Blanchard, James; Callis, Richard W.; Kessel, Charles E.; Kurtz, Richard J.; Lee, Peter J.; Mccarthy, Kathryn; Morley, Neil; Najmabadi, Farrokh; Nygren, Richard; Tynan, George R.; Whyte, Dennis G.; Willms, Scott; Wirth, Brian D.

    2014-03-13

    Several high-priority near-term potential research activities to address fusion nuclear science challenges are summarized. General recommendations include: 1) Research should be preferentially focused on the most technologically advanced options (i.e., options that have been developed at least through the single-effects concept exploration stage, Technology Readiness Levels >3), 2) Significant near-term progress can be achieved by modifying existing facilities and/or moderate investment in new medium-scale facilities, and 3) Computational modeling for fusion nuclear sciences is generally not yet sufficiently robust to enable truly predictive results to be obtained, but large reductions in risk, cost and schedule can be achieved by careful integration of experiment and modeling.

  12. Fusion materials science and technology research opportunities now and during the ITER era

    SciTech Connect (OSTI)

    S.J. Zinkle; J.P. Planchard; R.W. Callis; C.E. Kessel; P.J. Lee; K.A. McCarty; Various Others

    2014-10-01

    Several high-priority near-term potential research activities to address fusion nuclear science challenges are summarized. General recommendations include: (1) Research should be preferentially focused on the most technologically advanced options (i.e., options that have been developed at least through the singleeffects concept exploration stage, technology readiness levels >3), (2) Significant near-term progress can be achieved by modifying existing facilities and/or moderate investment in new medium-scale facilities, and (3) Computational modeling for fusion nuclear sciences is generally not yet sufficiently robust to enable truly predictive results to be obtained, but large reductions in risk, cost and schedule can be achieved by careful integration of experiment and modeling.

  13. GC GUIDANCE ON BARTER TRANSACTIONS INVOLVING DOE-OWNED URANIUM...

    Energy Savers [EERE]

    GUIDANCE ON BARTER TRANSACTIONS INVOLVING DOE-OWNED URANIUM GC GUIDANCE ON BARTER TRANSACTIONS INVOLVING DOE-OWNED URANIUM The Department of Energy has on a variety of occasions ...

  14. SU-E-I-93: Improved Imaging Quality for Multislice Helical CT Via Sparsity Regularized Iterative Image Reconstruction Method Based On Tensor Framelet

    SciTech Connect (OSTI)

    Nam, H; Guo, M; Lee, K; Li, R; Xing, L; Gao, H

    2014-06-01

    Purpose: Inspired by compressive sensing, sparsity regularized iterative reconstruction method has been extensively studied. However, its utility pertinent to multislice helical 4D CT for radiotherapy with respect to imaging quality, dose, and time has not been thoroughly addressed. As the beginning of such an investigation, this work carries out the initial comparison of reconstructed imaging quality between sparsity regularized iterative method and analytic method through static phantom studies using a state-of-art 128-channel multi-slice Siemens helical CT scanner. Methods: In our iterative method, tensor framelet (TF) is chosen as the regularization method for its superior performance from total variation regularization in terms of reduced piecewise-constant artifacts and improved imaging quality that has been demonstrated in our prior work. On the other hand, X-ray transforms and its adjoints are computed on-the-fly through GPU implementation using our previous developed fast parallel algorithms with O(1) complexity per computing thread. For comparison, both FDK (approximate analytic method) and Katsevich algorithm (exact analytic method) are used for multislice helical CT image reconstruction. Results: The phantom experimental data with different imaging doses were acquired using a state-of-art 128-channel multi-slice Siemens helical CT scanner. The reconstructed image quality was compared between TF-based iterative method, FDK and Katsevich algorithm with the quantitative analysis for characterizing signal-to-noise ratio, image contrast, and spatial resolution of high-contrast and low-contrast objects. Conclusion: The experimental results suggest that our tensor framelet regularized iterative reconstruction algorithm improves the helical CT imaging quality from FDK and Katsevich algorithm for static experimental phantom studies that have been performed.

  15. UNSAT-H Version 3.0: Unsaturated Soil Water and Heat Flow Model Theory, User Manual, and Examples

    SciTech Connect (OSTI)

    MJ Fayer

    2000-06-12

    The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve the above goals for assessing water dynamics and estimating recharge rates, the UNSAT-H model addresses soil water infiltration, redistribution, evaporation, plant transpiration, deep drainage, and soil heat flow as one-dimensional processes. The UNSAT-H model simulates liquid water flow using Richards' equation (Richards 1931), water vapor diffusion using Fick's law, and sensible heat flow using the Fourier equation. This report documents UNSAT-H .Version 3.0. The report includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plants, and the code manual. Version 3.0 is an, enhanced-capability update of UNSAT-H Version 2.0 (Fayer and Jones 1990). New features include hysteresis, an iterative solution of head and temperature, an energy balance check, the modified Picard solution technique, additional hydraulic functions, multiple-year simulation capability, and general enhancements.

  16. System Advisor Model

    Energy Science and Technology Software Center (OSTI)

    2010-03-01

    The System Advisor Model (SAM) is a performance and economic model designed to facilitate decision making for people involved in the renewable energy industry, ranging from project managers and engineers to incentive program designers, technology developers, and researchers.

  17. The iterative thermal emission method: A more implicit modification of IMC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Long, A. R.; Gentile, N. A.; Palmer, T. S.

    2014-08-19

    For over 40 years, the Implicit Monte Carlo (IMC) method has been used to solve challenging problems in thermal radiative transfer. These problems typically contain regions that are optically thick and diffusive, as a consequence of the high degree of “pseudo-scattering” introduced to model the absorption and reemission of photons from a tightly-coupled, radiating material. IMC has several well-known features that could be improved: a) it can be prohibitively computationally expensive, b) it introduces statistical noise into the material and radiation temperatures, which may be problematic in multiphysics simulations, and c) under certain conditions, solutions can be nonphysical, in thatmore » they violate a maximum principle, where IMC-calculated temperatures can be greater than the maximum temperature used to drive the problem.« less

  18. Technical Note: Measuring contrast- and noise-dependent spatial resolution of an iterative reconstruction method in CT using ensemble averaging

    SciTech Connect (OSTI)

    Yu, Lifeng Vrieze, Thomas J.; Leng, Shuai; Fletcher, Joel G.; McCollough, Cynthia H.

    2015-05-15

    Purpose: The spatial resolution of iterative reconstruction (IR) in computed tomography (CT) is contrast- and noise-dependent because of the nonlinear regularization. Due to the severe noise contamination, it is challenging to perform precise spatial-resolution measurements at very low-contrast levels. The purpose of this study was to measure the spatial resolution of a commercially available IR method using ensemble-averaged images acquired from repeated scans. Methods: A low-contrast phantom containing three rods (7, 14, and 21 HU below background) was scanned on a 128-slice CT scanner at three dose levels (CTDI{sub vol} = 16, 8, and 4 mGy). Images were reconstructed using two filtered-backprojection (FBP) kernels (B40 and B20) and a commercial IR method (sinogram affirmed iterative reconstruction, SAFIRE, Siemens Healthcare) with two strength settings (I40-3 and I40-5). The same scan was repeated 100 times at each dose level. The modulation transfer function (MTF) was calculated based on the edge profile measured on the ensemble-averaged images. Results: The spatial resolution of the two FBP kernels, B40 and B20, remained relatively constant across contrast and dose levels. However, the spatial resolution of the two IR kernels degraded relative to FBP as contrast or dose level decreased. For a given dose level at 16 mGy, the MTF{sub 50%} value normalized to the B40 kernel decreased from 98.4% at 21 HU to 88.5% at 7 HU for I40-3 and from 97.6% to 82.1% for I40-5. At 21 HU, the relative MTF{sub 50%} value decreased from 98.4% at 16 mGy to 90.7% at 4 mGy for I40-3 and from 97.6% to 85.6% for I40-5. Conclusions: A simple technique using ensemble averaging from repeated CT scans can be used to measure the spatial resolution of IR techniques in CT at very low contrast levels. The evaluated IR method degraded the spatial resolution at low contrast and high noise levels.

  19. Prototype indicators of value added through public involvement

    SciTech Connect (OSTI)

    Lach, D.; Hixson, P.; Ramonas, L.

    1995-12-01

    As more managers realize that public input in public sector decision making is a given in the current political and social climate, many are turning to public involvement as a way to manage input so that it is beneficial to their decisions and projects. Public involvement is starting to become a familiar way of doing business for many Federal agencies and its contractors. Yet, many, if not most agency and contractor managers are still unclear about the value and costs that public involvement adds to their projects. Proponents claim that public involvement increases the acceptability of project goals by increasing stakeholders` knowledge about and involvement in decisions of importance to them. In spite of these assertions avowing the benefits of public involvement, proponents have not generated methods that demonstrate or provide evidence of such value added through incorporating public involvement into projects. As these questions about the value and costs of public involvement efforts increase, there is a pressing need to document the value and costs of public involvement for the participants in these processes--the stakeholders--and to present this information to decision makers in ways that help them assess the value and costs of managing public input through a public involvement program.

  20. Lithium-vanadium advanced blanket development. ITER final report on U.S. contribution: Task T219/T220

    SciTech Connect (OSTI)

    Smith, D.L.; Mattas, R.F.

    1997-07-01

    The objective of this task is to develop the required data base and demonstrate the performance of a liquid lithium-vanadium advanced blanket design. The task has two main activities related to vanadium structural material and liquid lithium system developments. The vanadium alloy development activity included four subtasks: (1.1) baseline mechanical properties of non irradiated base metal and weld metal joints; (1.2) compatibility with liquid lithium; (1.3) material irradiation tests; and (1.4) development of material manufacturing and joining methods. The lithium blanket technology activity included four subtasks: (2.1) electrical insulation development and testing for liquid metal systems; (2.2) MHD pressure drop and heat transfer study for self-cooled liquid metal systems; (2.3) chemistry of liquid lithium; and (2.4) design, fabrication and testing of ITER relevant size blanket mockups. A summary of the progress and results obtained during the period 1995 and 1996 in each of the subtask areas is presented in this report.